Meeting the Regs [f-gas]

[chillerman2006]

Lets just say my f-gas ticket came from a xmas cracker & me know nothing

Advice please on correct procedure that meets f-gas to carry out the below repair

The system:

multi compressor system with common suction/discharge headers

remote condenser

20 attached evaporators

multiple isolation valves at expected locations

The fault to be repaired:

condenser leak

R's chillerman

[install monkey]

which brand of crackers do you buy?- i only get crap toys outta mine:confused:
theoretically upon diagnosing a leak, reclaim gas from system, repair leak,change driers, pressure test,vac, reweigh correct charge or calculate charge, recheck the leak within 28days- can be done on the same day.
if system holds over 3kg of refrigerant then update the fgas sheet with details of how much reclaimed,log the date of pressure test and date/sign.
log refrigerant additions as usually on your jobs most of the gas will be gone!haha
recheck oil levels are within reason- and dont buy anything from out the cases.[Q

but the supermarket way is- suspect leak on system, get big bottle of gas, lug it onto the roof, keep topping it up, and legget- manager happy, cases full,company can bill for big bottle of gas..

there is a section within the guidelines that state if a system cannot be shut down due to implications then it is ok to top up-
http://www.defra.gov.uk/environment/quality/air/fgas/

Lets just say my f-gas ticket came from a xmas cracker & me know nothing

Advice please on correct procedure that meets f-gas to carry out the below repair

The system:

multi compressor system with common suction/discharge headers

remote condenser

20 attached evaporators

multiple isolation valves at expected locations

The fault to be repaired:

condenser leak

R's chillerman

[install monkey]

CODE OF PRACTICE
FOR
REFRIGERANT LEAK TIGHTNESS
IN COMPLIANCE WITH THE
F-GAS REGULATION
VERSION 1 SUPPORTED BY
DECEMBER 2007
Page 1 of 28
DISCLAIMER
While BRA/FETA have made every effort to prepare this guide in
compliance with the requirements of current regulations and industry
practice, BRA/FETA can accept no responsibility for the
consequences of individual or corporate actions as a result of
following the code.
Page 2 of 28
Contents
Section 1 Introduction
i. Why the code of practice has been produced
ii. Who the code is for
iii. Scope of the code
iv. How the reader will benefit from the code
Section 2 Regulations, standards and directives
Introduction
•
Environmental Protection Act
•
F-Gas Regulation (EC) 846/2006
•
Ozone Depleting Substances Regulation (EC) 2037/2000
•
BS EN378/2000 Refrigerating systems and heat pumps –
Safety and environmental requirements.
•
BS EN378/2007 (Final draft) Refrigerating systems and heat
pumps – Safety and environmental requirements.
Section 3 Direct leak detection methods
Introduction
•
Fixed leakage detection systems
•
Portable electronic leak detectors
•
Ultraviolet (UV) indication fluids
•
Proprietary bubble solutions
•
New installation tightness test for leakage detection
procedure
•
Operational system tightness test for leakage detection
procedure
Section 4 Indirect refrigerant detection methods
Introduction
•
Visual
•
Manual checks
Section 5 Refrigerant detection system certification
Introduction
•
Sensitivity
•
Calibration
Page 3 of 28
Section 6 Individual competence and training
Introduction
•
Refrigerant handling
•
Brazing
Section 7 Removing refrigerant from the system
Introduction
•
Refrigerant recovery
•
Options for the reuse of refrigerants
•
Recovery for reclamation or destruction
Section 8 System charging
Introduction
•
Adding refrigerant after a small unknown loss
•
System recharge after large refrigerant loss
Section 9 Record logs
Introduction
•
Refrigerant usage
•
Maintenance records
Section 10 Appendices
Appendices
References
Bibliography
Other guidance
Page 4 of 28
Section 1 Introduction
This Code of Practice sets out the recommendations of the British Refrigeration
Association (BRA) for good practice in carrying out tightness testing for leakage
in Fluorocarbon refrigeration systems in commercial and light industrial
applications.
Whilst it is felt the Code of Practice cannot be exhaustive, it is nevertheless
thought to reflect the industry’s technical capabilities and technological
understanding, together with legislation and standards at the time of publication.
The Code of Practice should form the basis for users of refrigeration equipment
to provide the installing/servicing contractor/designer with requirements for
tightness testing for leakage in order that emissions of refrigerant are minimised.
The Code of Practice also identifies the competence requirements for individuals
performing leakage detection tasks in accordance with best practice and legal
requirements.
The Code of Practice emphasises the need for those designing, installing,
commissioning, servicing and maintaining refrigeration systems to take all
reasonable steps to minimise leakage potential.
Page 5 of 28
Section 2 Regulations, Standards and Directives
2.1 Introduction
There are Regulations, Standards and Directives that stipulate
requirements for tightness testing for leakage of refrigeration systems.
2.2 Environmental Protection Act 1990
Under the Environmental Protection Act the deliberate venting of
refrigerant is an offence.
Specific to the activities undertaken during the service and maintenance of
refrigeration systems the following actions could be construed as
deliberate venting.
1 The venting of “surplus” refrigerant from a system to atmosphere, if it is
considered that the system may be overcharged.
2 The venting of the refrigerant charge to atmosphere instead of
recovery when decommissioning a refrigeration system.
3 The use of refrigerant as a tracer for leak detection.
4 The process of “breaking a vacuum” with refrigerant during the process
of multiple evacuation of a refrigeration system.
5 The use of a refrigeration system or refrigerant container as a source
of pressurised gas for cleaning purposes.
6 The addition of refrigerant to a system thought or known to be leaking
before locating and rectifying the leaks.
The following actions could be construed as inadvertent loss:
1 Loss of refrigerant from leaking joints, seals, gaskets and cracked
pipes etc, before the leak has been detected and eliminated.
2 Loss of refrigerant from safety relief devices during operation to
prevent danger.
3 Loss of residual refrigerant dissolved in oil etc, after normal processes
of refrigerant recovery have been undertaken.
4 Loss of small quantities of refrigerant from “charging lines” such as
occurs during the normal service process of connecting and
disconnection to the system.
5 Loss of small quantities of refrigerant from sections of system pipework
or components, after having taken all practicable steps to recover
refrigerant.
6 Loss of small quantities of refrigerant along with non-condensable gas
only when the system is purged through a properly refrigerated noncondensable
gas purging device.
Page 6 of 28
Under the duty of care refrigerant being recovered would be classified as
“Controlled waste”. It would not be classified as “waste” if the recovered
refrigerant is recycled and returned to the original owner.
Also refer to Hazardous Waste Regulation requirements for handling and
movement of recovered refrigerant.
Section 33 of the Environmental Protection Act, states that it is illegal to
“treat, keep or dispose of a controlled waste in a manner likely to cause
pollution to the environment, or harm to human health”. Therefore care
should be taken to avoid accidental discharge of such controlled wastes
and ensure all who handle them are aware of Regulations.
Section 34 of the Act (Duty of Care) places a specific responsibility on
personnel who have control over any refrigeration system to ensure that
anyone undertaking tasks on their behalf does not allow these substances
to escape. If all of the elements of “actual power over the technical
functioning” as defined by the EU Commission, are devolved by the
operator to a third party through contractual arrangements, the authority of
operator and the responsibilities attached to it under the Regulation should
be deemed transferred to that third party.
2.3 F-Gas Regulation (EC) 846/2006
The F-Gas Regulation places duties on operators and personnel involved
in the manufacture, installation service and maintenance of applications
containing fluorinated greenhouse gases covered by the Kyoto Protocol.
Article 3 – Containment
Operators of stationary refrigeration, air conditioning and heat pump
equipment, shall:
1 prevent leakage of these gases, and
2 as soon as possible repair any detected leak.
Operators of these applications shall ensure they are checked for leakage
by certified personnel according to the following schedule:
1 applications containing
≥3kG shall be checked at least once every
12 months. This would not apply to hermetically sealed systems
containing <6kG.
2 applications containing
≥30kG shall be checked at least once every
6 months.
3 applications containing
≥300kG shall be checked at least once
every 3 months.
Page 7 of 28
The applications shall be checked for leakage within one month after a
leak has been repaired, to ensure the repair has been effective. The
British Refrigeration Association recommendation is that this shall be
carried out on a subsequent visit.
Operators of applications containing
≥300kG shall install leakage
detection systems. These systems shall be checked at least once every
12 months to ensure proper functioning.
Where a proper functioning leakage detection system is in place, the
frequency of the leakage inspections shall be halved.
Operators of applications
≥3kG shall maintain records on the quantity and
type of gas installed, and any quantities added and the quantity recovered
during servicing, maintenance and final disposal. They shall also maintain
records identifying the company or technician who performed
maintenance, as well as the dates and results of the leakage inspections.
These records shall be made available on request to the competent
authority and to the Commission.
Article 4 – Recovery
Operators of stationary refrigeration cooling circuits, air conditioning and
heat pump equipment shall be responsible for ensuring proper recovery by
certified personnel to ensure their recycling, reclamation or destruction.
Article 5 – Training and certification
At present, in the UK the minimum requirement for personnel handling FGas
refrigerants is either:
1 City & Guilds 2078 certificate in handling refrigerants.
2 CITB Safe handling of refrigerant certificate.
Consultations are continuing across the EU Commission Member states
and the above may be subject to change in 2008.
Ozone Depleting Substances Regulation (EC) 2037/2000
Under the Ozone Depleting Substances Regulation it is mandatory that
Chloroflurocarbon (CFC) and Hydrochloroflurocarbon (HCFC) refrigerants
are recovered, recycled or destroyed. The Regulation also states that it is
the user’s responsibility to ensure that applications containing
≥3kG are
checked for leakage annually and that appropriate steps are taken to
detect and remedy refrigerant leaks.
Page 8 of 28
2.5 BS EN378/2000 and EN378/2007 (Final draft) Refrigeration systems and
heat pumps – safety and environmental requirements.
This standard is intended to minimise possible hazards to persons,
property and the environment from refrigeration systems and refrigerants.
In doing so, it identifies the required design pressures for the system
based upon the type and design of the system, and the refrigerant utilised.
It further identifies the relationship between the design pressure and the
pressures for limiting devices, relief valve setting, rating for pressure relief
discharge, leakage test pressure and strength test pressure.
The minimum value of allowable design pressure shall be determined by
the minimum specified temperature given in the table below to determine
the saturated refrigerant pressure.
Ambient condition
≤32oC ≤38oC ≤43oC ≤55oC
High pressure side with air-cooled
condenser 55
oC 59oC 63oC 67oC
High pressure side with water
cooled condenser or water pump
Maximum leaving water
temperature +8K
High pressure side with
evaporative condenser 43
oC 43oC 43oC 55oC
Low pressure side with heat
exchanger exposed to outdoor
ambient temperature
32
oC 38oC 43oC 55oC
Low pressure side with heat
exchanger exposed to the indoor
ambient temperature
27
oC 33oC 38oC 38oC
When evaporators can be subject to high side pressure e.g. during gas
defrosting or reverse cycle operation, the high pressure side specified
temperature shall be used.
Page 9 of 28
The pressure relationships to which the system and components shall be
designed to meet relative to the maximum allowable pressure (
ps), are
given in the below.
Design pressure
≥ 1.0 x ps
System strength test pressure 1.1 to 1.3 x
ps
Tightness test pressure for assemblies
≥ 1.0 x ps
Safety switch device for limiting the pressure for
systems with relief device, setting
≥ 0.9 x ps
Safety switch device for limiting the pressure for
systems without relief device, setting
≥ 1.0 x ps
Pressure relief device, setting
≥ 1.0 x ps
Pressure relief valve achieves the required flow at
1.1
ps ≥ 1.1 x ps
Page 10 of 28
Section 3 Direct refrigerant detection methods
3.1 Introduction
Notwithstanding the legal requirements to identify and remedy refrigerant
leaks, there are other good reasons for this to be carried out:
1 Environmental impact – many refrigerants damage the ozone layer and
most also contribute to global warming.
2 Higher running costs – running costs will escalate as the leakage of
refrigerant reduces efficiency. This has a double impact on the
environment in that the lost refrigerant has an impact, but the
additional energy consumption of the system leads to greater carbon
dioxide emissions from power stations.
3 Increased servicing costs – these may include call out charges, finding
and remedying the leak, replacement refrigerant, possibly even the
replacement of a burnt-out compressor and consequent system
cleaning.
4 Health and safety hazards – dependant upon the refrigerant and the
location of the leakage, if it were into a confined space exposure levels
could potentially be exceeded leading to suffocation if sufficient loss
and displacement of air occurs.
3.2 Fixed refrigerant detection systems
There are a number of systems commercially available on the market.
These fixed multi point type systems monitor refrigeration installations for
refrigerant leakage continuously, recording the levels of refrigerant
detected. These devices can be configured to activate different alarms
dependant upon the level of refrigerant detected.
The F-Gas Regulation identifies a legislative requirement for a fixed
leakage detection system to be installed on all refrigeration systems
containing
≥300kG of fluorinated greenhouse gases.
As with portable refrigerant detectors, different refrigerant detection
technologies exist, and suitability of the application and refrigerant should
be verified with the system manufacturer.
System design:
The following points should be considered at the design stage:
•
Areas to be covered for refrigerant detection – sample points
should be in locations of historical leakage and susceptible areas
e.g. compressor housings, plant rooms, packs/plant, condenser
Page 11 of 28
headers, receiver assemblies, suction/liquid filter drier assemblies,
valve stations, evaporator coils, bases of pipe work risers etc.
•
Number of sample points allocated per detector channel – a system
with a greater number of sampling points will generally provide
greater coverage increasing potential to detect refrigerant.
•
If there is more than one refrigerant utilised in the installation.
•
If confined spaces exist that require monitoring for safety reasons,
covering these areas ensures compliance with BS EN378:2000
(BS EN378:2007).
•
How alarms are to be enunciated – consider alerting employees at
risk from asphyxiation from localised leakage in confined areas.
This can be by a warning beacon/sounder or a relay connection to
a building management system (BMS).
•
What should be done with the data generated by the system – an
IP addressable system enables remote monitoring to continually
retrieve alarms events and fault data and automatically initiate an
alarm via e-mail, SMS or fax. Response times and reports can be
generated to provide an overview of performance.
System installation:
The monitor should be located to be easily accessible for manual
interrogation and maintenance.
Systems that utilise sample tubing should ensure that the pipework
is not:
•
Installed such that kinking or flattening can occur
•
Run from a very warm to very cold space
•
Installed with a corner radius less than 150mm
•
Sample points should be installed facing down
•
“split” sample pipes should be of equal length from the junction to
sample point
•
All pipework to be securely clipped to cable tray and not restrict
access to other equipment
Commissioning:
Commissioning should be carried out by the manufacturer/supplier
of the system to ensure:
•
The system is set up and configured to factory specification and
tolerances
•
Each channel is configured to correct requirements for the area
under cover i.e. refrigerant, concentration level for alarm
•
All connections to remote alarms and/or BMS system are tested
•
IP address for the unit if connected to Local or Wide Area Network
is configured
•
Appropriate training and instruction is provided to appropriate
personnel, both maintainers and operators of the system.
Page 12 of 28
3.3 Portable electronic refrigerant detectors
There are ranges of portable electronic refrigerant detectors that are
sensitive to leakage rates as small as 3 g/yr. The selection of these
devices must be made to ensure that their suitability for the refrigerant
within the system.
Caution should be taken to use suitable electronic refrigerant detection
devices with Hydrocarbon (HC) refrigerants due to their flammability.
For the most part, there are four types of electronic refrigerant detection
devices:
•
Corona discharge
•
Heated diode
•
Infrared
•
Ultrasonic
In all cases individual manufacturer’s data should be consulted to verify
suitability.
Whilst carrying out refrigerant detection inspections in plant areas it may
be necessary to temporarily isolate ventilation systems and compressor
cooling fans.
3.4 Ultraviolet (UV) indication fluids
Refrigerant detection systems have been developed using a fluorescent or
coloured dye which is added into the system and is distributed throughout
the system with the lubricant, it indicates leaks by its emission with the
leaking refrigerant. The refrigerant evaporates and the additive remains at
the site of the leak. This becomes visible under an ultraviolet lamp. Care
must be taken with this method to ensure compatibility with system
components, and the compressor manufacture should be consulted to
authorise its' use. The client or operator of the system should also be
consulted for consent to the fluid being utilised. There is no reaction with
the refrigerant therefore the use of this method is not limited to
fluorocarbon refrigerants.
It should be noted that the effectiveness of this method of leakage
detection will be significantly reduced in systems with efficient oil
separation devices.
Page 13 of 28
In order for this method to be most effective it is important that any
emitted fluid is thoroughly cleaned from the components once the area of
leakage has been identified and the leak remedied.
3.5 Proprietary bubble solutions
Possibly the simplest and the most sensitive of methods of tightness
testing for leakage is a “weak soap” solution applied to the area being
tested. Commercially available purpose made liquids are recommended
for this procedure, as these make this task easier and cleaner.
This method would be unsuitable if the system or section being tested
is operating in a vacuum.
The use of this method should be considered in conjunction with the use
of portable electronic refrigerant detection devices.
Page 14 of 28
REFRIGERANT TIGHTNESS TESTING FOR LEAKAGE INSPECTION PROCEDURES
- OPERATIONAL SYSTEM -
Indirect refrigerant detection
Direct refrigerant detection
Proceed to direct
refrigerant detection
methods.
1. Checking
system logbook
2. Visual
inspection of
system
components
3. Visual
inspection of
system safety
devices
4. Visual
inspection of
system refrigerant
charge
5. System
tightness test for
leakage
6. Logbook 7. Re-inspection
of repair
* Inspection and
analysing service
and maintenance
records and
inspection reports.
* Inspection of
refrigerants
handling reports.
(recharging,
recovery etc)
* Inspection of
system data –
design and
operating.
Inspection
for…
- noises
- vibrations
- corrosion
- oil leakage
- material
damages
- component
breakdown
- sight
glasses
… leading to
risks for ref.
leakage
Inspection of
technical condition
for…
- safety devices
- pressure limiter
(HT/LT)
- gauges
- sensors
- outlet discharge
lines
Set values
inspection for…
- safety devices
- pressure limiter
(HT/LT)
Inspection of system
refr. Charge by…
- sight glasses
- level indicators
System pressure
check…
- operating pressure
- operating
temperature
Refrigerant
detection
inspection by…
- electronic
portable detection
sensitivity to be
5grms/yr
Supplementary
checks by…
- bubble solution
- UV fluid
Areas to check…
- joints
- valves/stems
- seals
- vibration areas
- seals on
replaceable
filters/driers
- cons to safety
operating devices
Update and
detailed
reporting of
results on
leakage
inspection
Mandatory reinspection
within 30
days, can be on
same day at
suitable time period
Mandatory repair
of detected leak
Page 15 of 28
REFRIGERANT TIGHTNESS TEST FOR LEAKAGE INSPECTION PROCEDURE
- NEW SYSTEM PRESSURE TEST -
1. System design & test
pressures
2. Visual inspection of
system & components
3. System strength test 4. System tightness test 5. Operating system tightness
test for leakage inspection
Analyse system design to
establish…
- design pressure Ps
- limiting device pressure
- tightness test pressure
- relief device pressure
- strength tests pressure
Inspect for…
- Pressure test safety
devices
- component working
pressure
- isolation/removal of
components unable to
withstand strength test
pressure
Undertake system strength
test…
In accordance with the
requirements of BS EN
378/2000
Reduce strength test pressure to
tightness test pressure…
Record temperatures
Inspect for leakage with bubble
solution
Test pressure duration - 24hrs
recommended, minimum 6hr
Carry out steps 2-7 of operating
system tightness test for leakage
inspection procedure.
Log book…
Record results of test
Log book…
Record results of inspection
Re-test if necessary
Page 16 of 28
Section 4 Indirect refrigerant detection methods
4.1 Introduction
In addition to direct refrigerant detection methods, good practice during
the service and maintenance procedures by employing indirect refrigerant
detection techniques may identify a requirement for further direct
refrigerant detection procedures to be implemented.
Manual checks – Refrigerant loss may be identified by carrying out
manual checks of the system and its operating conditions against the
design operating conditions, by analysis of one or more of the following
parameters;
- Pressure
- Temperature
- Compressor current
- Liquid level
- Recharge volume
Refrigerant loss indication – Any presumption of refrigerant loss shall be
followed up by an examination of tightness testing for leakage using a
direct method as described for an operational system.
Refrigerant loss presumption – One or more of the following conditions
being experience would constitute the presumption of refrigerant loss;
•
A fixed refrigerant detection system indicates refrigerant
detection
•
The system produces abnormal noises, vibrations, ice formation
or insufficient cooling capacity
•
Indications of corrosion, oil leaks, component or material
damage at possible leakage points
•
Indication of refrigerant loss from sight glasses or level
indicators or other visual aids
•
Indications of damage in safety switches, pressure switches,
gauges and sensor connections
•
Deviations from normal operation conditions indicated by the
parameters analysed, including readings from real time
electronic systems
•
Other signs indicating refrigerant charge loss.
Page 17 of 28
Section 5 Refrigerant detection system certification
5.1 Introduction
There are no Regulations, Standards or Directives at the time of
publication that stipulate the minimum requirement for the level of
sensitivity for static or portable electronic refrigerant detection devices, or
the requirement and frequency for calibration of these devices. In the
absence of this detail and to ensure sufficient provision exists to achieve
adequate levels of refrigerant detection, the following levels of sensitivity
and frequency of calibration are recommended.
5.2 Sensitivity – the recommended sensitivity level in the absence of
legislative requirement for fixed and portable electronic leakage detection
devices is 5 g/yr.
5.3 Calibration – to ensure reliable operation of fixed refrigerant detection
devices is maintained, and in the absence of a legislative requirement, it is
recommended for these devices to be calibrated every 12 months.
Fixed refrigerant detection devices should be serviced and calibrated by
the manufacturer or an approved agent. A certificate of service and
calibration should be issued to the operator of the fixed refrigerant
detection system.
For portable electronic refrigerant detection devices the recommended
frequency for calibration by the British Refrigeration Association is every 3
months. Calibration can be self-certified by the user employing a
measured calibration leakage device available from the manufacturer of
the refrigerant detection device. A record of the calibration must be
maintained by the operator of these devices and be made available for
inspection upon request by the operator of the refrigeration system, with
whom the responsibility for maintaining records for F-Gas Regulation
compliance lies.
Page 18 of 28
Section 6 Individual competence and training
6.1 Introduction
In order that the task of refrigerant loss detection and system pressure
testing is carried out safely and effectively, it is necessary that minimum
levels of individual competence and training is identified and accreditation
acquired by the individual or company.
6.2 Refrigerant handling
The F-Gas Regulation at the time of publication has identified the
minimum level of training requirement for personnel handling F-Gas
refrigerants to be either:
•
City & Guilds 2078 certificates in Handling Refrigerants
•
CITB Safe Handling of Refrigerants certificate
Consultations are continuing across the EU Commission Member states
and the above may be subject to change in 2008.
6.3 Brazing
Installers of new and those altering existing systems under the Pressure
Equipment Directive are required to be certified to the appropriate level
dependant upon the level or category of joint being made under the
Directive.
For most commercial applications an “industry recognised”
qualification level suitable for Sound Engineering Practice (SEP) and
category 1 as defined by the Pressure Equipment Directive can be brazed
by personnel qualified as a minimum to:
•
The British Refrigeration Association’s Specification for Brazing and
Brazer Assessment.
Category 2, 3 and 4 joints can only be made by personnel certified by a
third party assessor, this invariably being a Pressure Equipment Directive
Notified Body.
Page 19 of 28
6.4 Leakage detection inspection
Personnel undertaking refrigerant loss detection and inspection activities
shall;
•
Be qualified for refrigerant handling as 6.2.
•
Have awareness and understanding of the system design,
operation and performance criteria.
•
Understand the operating pressures within the system and have
the ability to interpret against system design.
•
Have sufficient knowledge of areas of the system susceptible to
refrigerant loss.
•
Inspect the log book to identify areas having had refrigerant loss
and carry out close examination.
•
Thoroughly and systematically inspect all parts of the system that
are regularly accessed and maintained.
•
Have available calibrated equipment designed for the task in hand.
•
Be approved by their employer to competence levels
commensurate with the specific task being undertaken.
•
Have the brazing competence levels needed to satisfy the
requirements of the Pressure Equipment Directive when carrying
out remedial works.
•
Inspect and identify any potential areas where future refrigerant
loss may occur.
Page 20 of 28
Section 7 Removing refrigerant from the system
7.1 Introduction
Once a system has been identified as having a leak, in order to effect a
repair it is necessary to remove refrigerant from the section concerned,
and it will be necessary to isolate the leaking component or section of the
system. Pumping the system down in order to achieve this is unlikely to be
sufficient, recovery of the refrigerant will be necessary.
Removal of refrigerant is also necessary when the system is
decommissioned at the end of its useful life.
7.2 Refrigerant recovery
Removal of refrigerant from a system can be achieved in numerous ways
of varying degrees. For example, liquid refrigerant can sometimes be
transferred into recovery cylinders by using the system’s own pressure,
but this will not remove all the system charge, and it will be necessary to
utilise a recovery machine to recover the vapour left in the system.
Alternatively recovery machines are available that can recover liquid
refrigerant and the residual vapour.
Recovered refrigerant must only be stored in special purpose recovery
cylinders – cylinders for new refrigerants must not be used.
Whilst recovering refrigerants it is essential that the cylinder is not
overfilled. Whenever refrigerant is being transferred into a cylinder it must
be continuously and accurately weighed. The maximum permissible
contents of a cylinder are printed on its data plate. The figure is a variable
depending on the density of the refrigerant. A general guide of 80% of the
cylinder volume is usually used.
Some “high” pressure refrigerants e.g. R410A may require specific
recovery cylinders.
There is no practical way of separating and reprocessing refrigerant
mixtures, therefore, care is required to avoid mixing of refrigerants. Mixed
refrigerants have to be destroyed – a process which should be avoided as
it is costly in financial and energy terms and the refrigerant is lost for future
use.
Page 21 of 28
There are three categories that are used when defining the recovery and
reuse of refrigerants:
Recovery – To remove refrigerant from a system and transfer it to an
external cylinder. Depending upon the equipment used, the refrigerant
may or may not be treated in some way or have its condition tested.
Recycling – To treat used refrigerant to remove contaminants such as oil,
moisture, acid and particulate matter. This is typically achieved by passing
the refrigerant one or more times through an oil separator and filter drier
cores.
Reclamation – To reprocess the recovered refrigerant to virgin standard
quality and specification.
7.3 Options for the reuse of refrigerants
When repairing, maintaining or decommissioning a system, there are
various options that can be employed:
•
Recover and reuse refrigerant in the original system
•
Recover, recycle and reuse by original owner
•
Recover, reclaim and reuse by original owner
•
Recover, reclaim and make available for reuse by others
•
Recover and destroy
Refrigerant that has been simply recovered should only be used in the
system from which it was taken.
Recycled refrigerant should only be reused in systems belonging to the
same owner.
Only refrigerant reclaimed to virgin quality and original specification should
be sold or used in equipment of different ownership.
Grossly contaminated and mixed refrigerants have to be destroyed as
they are unsuitable and cannot be reclaimed.
Page 22 of 28
7.4 Recovery for reclamation or destruction
When refrigerant is transferred from a system as a liquid, the cylinder shall
display a warning that the refrigerant may contain contaminants. Having
recovered the refrigerant the system will retain any contaminants (oil,
water, acids and particulate matter) Disposal of this oil must be in
accordance with the requirements of the Hazardous Waste Regulation.
Recovered refrigerants should be returned to the original supplier or to a
similar organisation for reprocessing or destruction. Transport and
movement of the refrigerant must also be in accordance with the
requirements of the Hazardous Waste Regulation.
Page 23 of 28
Section 8 System charging
8.1 Introduction
In order for the refrigeration system to operate efficiently it must contain
the correct quantity of refrigerant. On a new system this will have been
calculated and form part of the commissioning documentation.
There are two methods of adding refrigerant into the refrigeration system
by gas or liquid. When the refrigerant is a Zeotropic blend it must be
removed from the cylinder as a liquid, as if it is not, the composition will
change and the system performance may be affected. Charging points
should be incorporated into both high and low pressure sides of the
system to allow refrigerant to be charged in the appropriate form.
The hoses and manifold used to charge refrigerant must not contain air or
another refrigerant, to remove this either evacuate them or purge. When
purging use refrigerant in vapour form and at the lowest possible pressure.
Refrigerant can be added to a system in two possible ways:
•
As liquid into the receiver or liquid line. This is usually done after
the system has been evacuated prior to initial start up.
•
As a gas into the suction line, this is usually done when the system
is running and is being topped up. Never add liquid into the suction
line.
NOTE
If charging a Zeotropic blend into the suction line, it is necessary to
evaporate (flash off) the liquid by throttling the low side valve of the
charging manifold, proprietary devices for use in conjunction with a
charging manifold are available for this purpose.
New refrigerants should not contain any contamination, but, to be safe it is
recommended to incorporate a filter drier in the charging line.
Reclaimed refrigerants should only be used from a recognised source to
ensure it is of a proven purity of acceptable standard.
Recovered refrigerant should only be reused in the system from which it
was recovered from, to avoid any potential for cross contamination.
Page 24 of 28
The weight of refrigerant must be recorded and entered onto the record
log as required under the F-Gas Regulation.
8.2 Adding refrigerant to a system that has lost a small but unknown quantity
of refrigerant.
On small or critically charged systems, the residual charge should be
recovered and re-charged weighing in refrigerant to the same weight as
originally charged into the system at commissioning.
On larger commercial type systems, where the remaining quantity of
refrigerant cannot be identified, the addition of refrigerant can be in two
possible ways:
•
As liquid into the receiver or liquid line. This is usually done after
the system has been evacuated prior to initial start up.
•
As a gas into the suction line, this is usually done when the system
is running and is being topped up. Never add liquid into the suction
line.
For Zeotropic refrigerant additions refer to the charging procedure
previously described.
Refrigerant should be charged into the system until there are no bubbles
observed in the sight glass when the system is operating at design
conditions. The sight glass should not be solely relied upon, system
operating pressures and temperatures, compressor current and
temperatures should be as recorded in the commissioning log. Recorded
operating levels should also be considered.
The weight of refrigerant must be recorded and entered onto the record
log as required under the F-Gas Regulation.
8.3 Adding refrigerant to a system that has lost a large proportion of the
refrigerant charge.
In the event of a large refrigerant loss from a system containing a
Zeotropic refrigerant, and where the loss has occurred from the vapour
side of the system where the potential for fractionation exists, the
remaining refrigerant should be recovered from the system and the
system recharged with new refrigerant.
Page 25 of 28
Section 9 Record Logs
9.1 Introduction.
In order that a detailed history of the work undertaken on the refrigeration
system is available to service personnel and the operator a suitable record
of such should be maintained and be available at site level to operative
undertaking any works on the system.
9.2 Refrigerant usage.
The F-Gas Regulation states that operators of stationary refrigeration, air
conditioning and heat pump applications containing 3kG or more of
fluorinated greenhouse gases, shall maintain records of the quantity and
type of refrigerant installed, any quantities added and the quantity
recovered during servicing maintenance and final disposal. They shall also
maintain records of other relevant information including the identification of
the company or technician who performed the servicing or maintenance
as well as the dates and results of leakage checks carried out. These
records shall be made available upon request to the competent authority
and to the Commission.
An example record log is provided on the DEFRA web site, see
Appendix I.
9.2.1 BS EN378:2000 (BS EN378:2007 Final draft) identifies a requirement for
an updated log-book to be maintained for refrigeration systems.
The following information shall be recorded in the log-book:
•
Details of all maintenance work and repairs
•
Quantities, kind of (new, re-used or recycled) refrigerant charged
on each occasion, and quantities transferred from the system on
each occasion
•
If there is an analysis of re-used refrigerant, the results shall be
kept in the log-book
•
Source of re-used refrigerant
•
Changes and replacements of components of the system
•
Results of periodic routine tests
•
Significant periods of non-use.
Page 26 of 28
Section 10 Appendices
10.1 Appendices
Appendix I DEFRA Record log sample
10.2 Reference
Regulation (EC) No 842/2006 - F-Gas Regulation.
Regulation (EC) 2037/2000 - Ozone Depleting Substances
Environmental Protection Act 1990
Pressure Equipment Directive 1999
Hazardous Waste Regulations 2005
10.3 Bibliography
DETR Good Practice Guide 178
CITB Safe Handling of Refrigerants
BS EN 378:2000 Refrigeration systems and heat pumps – safety
and environmental requirements.
(BS EN 378:2007 Final draft) Refrigeration systems and heat
pumps – safety and environmental requirements.
10.4 Other guidance
British Refrigeration Association Guide to Good Commercial
Refrigeration Practice
Institute of Refrigeration Code of practice for the minimisation of
refrigerant emissions from refrigeration systems
Institute of Refrigeration safety code for refrigerating systems
utilising group A1 and A2 refrigerants
Page 27 of 28
Page 28 of 28
Produced and published by the
BRITISH REFRIGERATION ASSOCIATION
An incorporated Association of the Federation of Environmental
Trade Associations Ltd (FETA)
2 Waltham Court, Milley Lane,
Hare Hatch, Reading, Berks RG10 9TH
Tel: 0118 940 3416
Fax: 0118 940 6258
E-Mail:
info@feta.co.uk
Web:
www.feta.co.uk

[chillerman2006]

but the supermarket way is- suspect leak on system, get big bottle of gas, lug it onto the roof, keep topping it up, and legget- manager happy, cases full,company can bill for big bottle of gas..

there is a section within the guidelines that state if a system cannot be shut down due to implications then it is ok to top up-
http://www.defra.gov.uk/environment/quality/air/fgas/











Thanks Install

not so sure about the supermarket way though ;)

wheres this bit about implications ?

and would it include vent and purge to keep customer happy and keep a large contract ?

R's chillerman

[install monkey]

ec.europa.eu/clima/policies/f-gas/docs/2011_study_en.pdf
click on the first site- happy reeading!!

[chillerman2006]

Lets look at another option, is this allowed ?

isolate compressor discharge valves and discharge header

also isolate receiver outlet and liquid line

giving double isolation on both sides of condenser

then transfer condenser/reciever/discharge line to low side or another pack

purge condenser with nitrogen, repair leak/s

vac to low torr and holds ok

Now what next ?

Open up system to condenser ? [risking venting if still a leak]

Pressure/strength test ? [risking contaminating refrigerant with ofn if valves pass]

Or is this all a deffo no & regardless of what the customer insists will be max down time

The whole system is to be recovered, repaired in the correct manner and strength/pressure tested & correctly vacced prior to re-charging

R's chillerman

[install monkey]

forgot to mention- also you will have completed ur risk and method statements-stating how you are going to carry out the task, which is usually checked by a competant person prior to the work undertaken.

out of intrest, a leakin schraeder core-that can be changed with a core removal tool, would that req pressure testing, even though its usually capped with a rubber gasket or flare nut and copper bonnet?

[chillerman2006]

ec.europa.eu/clima/policies/f-gas/docs/2011_study_en.pdf
click on the first site- happy reeading!!

Install

nothing to click ???

R's chillerman

[chillerman2006]

forgot to mention- also you will have completed ur risk and method statements-stating how you are going to carry out the task, which is usually checked by a competant person prior to the work undertaken.

out of intrest, a leakin schraeder core-that can be changed with a core removal tool, would that req pressure testing, even though its usually capped with a rubber gasket or flare nut and copper bonnet?

risk assessments and method statements will be generic and will state repair to comply with regs ect

oh go on, only been back a while and your gonna hijack me thread over a schraeder ;) good point though

R's chillerman

[install monkey]

deffo no no- transferring gas to another system- gas must be transferred to a dedicated container ,labelled, and also weighed whilst filling.
what sites u workin on, so i can report you?
pressure test must be with either nitrogen or trace helium and nitrogen mix if using leak spray- maybe a trace of refrigerant if using electronic leak detector- it can be difficult trying to tell a shop manager ur gonna knock half his kit off,to carry out a by the book repair- but if its done right its gonna save your company money and you might find other leaks whilst leak testing

[chillerman2006]

Hmmm ok

So I cant transfer to another system for safe storage ;)

Recover to bottle or transfer to low side then and now what do I do once repaired

Can I open up the system after vaccing to low torr and holding ok ?

Or with my double isolation in place can I strength test my brazing ?

R's chillerman

ps: I dont work anywhere this is all hyperthetical !

[install monkey]

Hmmm ok

So I cant transfer to another system for safe storage ;)
NO
Recover to bottle or transfer to low side then and now what do I do once repaired
PRESSURE TEST TO PROVE INTEGRITY
Can I open up the system after vaccing to low torr and holding ok ?
NO-A 30INCH VAC IS EQUIVELENT TO A 2BAR PRESSURE TEST
Or with my double isolation in place can I strength test my brazing ?
NO
R's chillerman

ps: I dont work anywhere this is all hyperthetical !
GOOD JOB YOU DONT WORK ANYWHERE WITH THOSE PRACTISES HYPOTHETICAL OR NOT:mad:

[chillerman2006]

Right, I am learning here ;)

So its no no no, but you say i can pressure test to prove integrity

Can I do that with refrigerant to avoid contamination of isolated refrigerant ?

If not what pressure can I pressure test with ofn to in my double isolated condenser area ?

R's chillerman

[install monkey]

http://www.refrigeration-engineer.com/forums/showthread.php?18192-Pressure-Strength-Test-Duration

[chillerman2006]

Hmmm

So although the reciever has not been repaired only the condenser

Does this now mean I have to be working to the PED regs too now ?

This also throws up another question, reciever end plug leaking

Should this be tested to F-Gas, EN378 or PED ?

This is all very confusing !

R's chillerman

[install monkey]

ped regs mainly refer to the design,construction of the vessel (reciever)and its safety devices mainly prv,bursting disc, calibration/rating. oh and wall thickness/internal rust-if this was the case then it would req inspecting by an insurance assessor yearly- not my trade this but hey ho.
as for a leaking reciever plug-fusible or blanking- do you try giving it a 1/4 turn to see if that rectifys the leak,-with 20bar behind it-consequences of dropping all the gas, or do you degas it,pressure test it,vac and have a big repair cost, all safely done and an unhappy site manager

[chillerman2006]

Argh I see

No, not a fusible plug or blanking plug, deffo not with 20 bar of liquid behind it

But then if its a level indicator sightglass that might be ok, what you think ?

R's chillerman

ps: is it only you and I on here tonight ?

[install monkey]

yep,i got no mates/or manning the fort-haha
any type of fitting, 1/4 flare nut, bulls eye on any fluid level indicator- may seem petty but its down to the engineers discretion whether they just nip it up and usually all is ok, but if u nip it up and it bursts- then youve got cabinets full of stock and a bill for gas- and youve gotta explain it to the manager.

[monkey spanners]

I'd probably recover the gas into the low side, fix leak, pressure test with nitrogen but under what the low side standing pressure is (don't think the leak testing pressure is a set pressure) if ok vac and let gas back in then run up and get the head pressure up and double check it :o

If its a braze then i've never had one leak thats passed a visual inspection, mechanical joint would be different.

[chillerman2006]

I'd probably recover the gas into the low side, fix leak, pressure test with nitrogen but under what the low side standing pressure is (don't think the leak testing pressure is a set pressure) if ok vac and let gas back in then run up and get the head pressure up and double check it :o

If its a braze then i've never had one leak thats passed a visual inspection, mechanical joint would be different.

Nice one MS

pressure test with ofn below current low side pressure to prevent risk of passing through isolated valves

also I like the 100% pass rate on the visual strength/pressure test ;)

R's chillerman

[stufus]

Had a leak on a McQuay chiller a while back condenser coil leaking.
Isolated discharge and liquid lines in and out off condenser, reclaimed what was in it .
Welded her up and vacced it down ,All held tickety boo.
Lobbed the gas back in and ran her up and performed leak test while running under full load.
All in under 3hrs, water temp remained within range for application a a crisis was averted in a data center.
Don't give a monkeys what the FGAS police have to say about it .
The bottom line is no refrigerant other than that which had initially been lost due to original leak was released.
At some stage common sense has to prevail.
Far to many grey area's for the pencil pushers to pull another ace.
Cheers
Stu

[chillerman2006]

Nice one Stu

as an engineer of your calibre am sure when you inert brazed the joint you would of raised the pressure a tad when finished just to keep the ''pencil pushers'' happy ;)

R's chillerman

[stufus]

I purged while brazing alright ,problem being I only had a 10ltr nitro with me and there was fook all in it.
The highest it got was about 1/4 bar :-)
But it's still chugging away and leak free.
The pencil pushers will always find way's to keep themselves happy.
The majority of the members here are conscientious about what we do and are better trained and placed than any one to make the "right" decision .
Cheers
Stu

[al]

If i can stick me two cents in;

From reading the fgas directly there is no specific mention of transferring refrigerant that i can see, if it speeds repair then isolate condenser, recover gas to a suitable container, this could be the low side of the system or to another system.

The repair does not necessarily have to be strength tested, this is reserved for PED certification, not generally for a repair, a leak test would suffice at a pressure that the shut off valves can with hold.

i have tightened leaking nuts/glasses on receivers, but only by a bare 1/8 turn, if this doesn't seal it recover gas and spray paint fitting, pull a good deep vacuum and leak test, worked a treat on York chiller fittings:)

One other point on PRV's, these must be replaced every five years and certification left on site.

Above all if customer refuses permission to carry out works then document this and as soon as practical implement a repair.

Alternatively go on a long sunny holiday.

al

[Gibbo]

Interesting read guys, it is a bit of a minefield out there.
As for leak testing with nitrogen say on the high side with refrigerant in the low side isolated with service valves personally i would feel happier recovering the lot and pressure testing the whole unit but thats just my 2 cents worth. I'm sure guys are doing all sorts of variations.

Gibbo

[Rob White]

.

What you have to understand is the definition of a pressure test.

On a new installation or after a substantial modification / alteration
then a structural integrity strength test is required.

To prove the system is gas tight then a gas tightness test is conducted.

Non of those two tests are used for leak finding. Leak finding can be done
at any pressure and is better if it is kept as low as possible, it can be a
lot lower than the valves would hold so cross contamination of the N2 into
the refrigerant would be greatly reduced.

Regards

Rob

.

[install monkey]

tighness test should be carried out at 1.0 x maximum operating pressure
Tightness test pressure for assemblies
≥ 1.0 x ps
so either your not complying to the guidelines for the tightness test or risk contaminating your refrigerant- double edged sword


.

What you have to understand is the definition of a pressure test.

On a new installation or after a substantial modification / alteration
then a structural integrity strength test is required.

To prove the system is gas tight then a gas tightness test is conducted.

Non of those two tests are used for leak finding. Leak finding can be done
at any pressure and is better if it is kept as low as possible, it can be a
lot lower than the valves would hold so cross contamination of the N2 into
the refrigerant would be greatly reduced.

Regards

Rob

.

[al]

Tightness test is generally install only, first and initial commissioning. The rest is leak test, also the pressure for tightness test would be as per the CE cert on the plant, but this would not be a practical test in my opinion?

al

[stufus]

Just spit on it ! No bubbles , good to go.Not sure about fridge systems , but it works on the missus:p
Cheers
Stu

[Rob White]

.

Don't confuse tightness testing for leak testing.

One prooves the system is gas tight (tightness testing)
and the other is for finding leaks.

By definition if you have a leak it can't be gas tight
and again by definition if it is gas tight it can't have a leak.

It might be playing with words but they are the actual definitions
and as pedantic as it seems they are how the standards ar written.

Prooving a system is gas tight is opposite to prooving it has a leak.

Regards

Rob

.

[chillerman2006]

Thanks for all the replys Gents

it certainly is a ''minefield out there''

and if it can be confusing and missinterpreted by us, whats it like for newbies just cutting their teeth in the game !

Transfering from one system to another may seem odd to those working on smaller systems or chiller and industrial systems but from one pack to another is normal procedure to keep down time to a minimum and prevent stock loss, there is also the fact that they often install new cases to an old system and tubework or new system on old cases, so cross contamination is not a high priority here.

Also working on an all in service contract you dont have the luxury of time for a fall decant of a system and have absolutely no chance of a store saying ''yeah its ok to shut a pack down and a full island of cases plus cold rooms'' for days.... and as we all know the customer is king !

The leak test is at the pressure the engineer feels comfortable with to believe they have no leaks and can do so safely without risking passing any valves.

And I also agree a good engineer knows when they have got a braze right and know when its been awkward and may fail the leak test.

It still seems to me its all about the engineer making an educated decision on how a repair should be carried out depending on their current environment and circumstances as we still have regs that allow for mixed interpretation.

Regards Chillerman

[Rob White]

Thanks for all the replys Gents


It still seems to me its all about the engineer making an educated decision on how a repair should be carried out depending on their current environment and circumstances as we still have regs that allow for mixed interpretation.

Regards Chillerman

I agree.

The regs state "all reasonable precautions must be taken".

The only trouble with being reasonable is differant people
have differant definitions of the word.

Ultimately it might have to be decided in court and that is
when you hope your lawyer is better than theirs :confused:

Regards

Rob

.

[wheresmyspanner]

If everything was done right first time then none of this would exist and there wouldn't be any grey areas, unfortunatly the greed of the supermarkets/clients puts pays to this.

Where I started in the trade we had to pressure test for 12 hours to prove the system to ourselves before presenting it to the client for another 6 hours, same applied for a vac test. Yes it took a while but it never ever bounced back, then again it was for stuff that mattered.