But is it smart??

[VGV]

Hi guys,

Over the years have on many occassions observed a technician apply a torch to the exterior of an ammonia cylinder to hasten the charging process, or torch a pipe section ahead of a jacked open solenoid valve at an evaporator to clear the pipe of ammonia prior to valving off downstream and opening for strainer inspection.

But, is it smart??

VGV

[Grizzly]

warming a cylinder to increase it's internal pressure, thereby facilitating a faster refrigerant transfer. Or warming a refrigerant line to speed up the removal of liquid / vapour from within.
Is a well established procedure and in some scenarios very necessary!
What is open to interpretation is the means of applying the HEAT.
I would encourage caution with the use of a naked flame.
But in extreme cases I have done so
myself.
Normally I prefer to use a hot air gun.
You have to consider the temperature and pressure differentials that can be created.
Any fridge work requires patience.
Basically increase the heat load and increase the risk!
The choice is yours!
May I also add that with fridge systems there is normally lots of combustable materials around.
Need I say more.
Grizzly

[NH3LVR]

Heating a strainer in an Nh3 system is a acceptable technique. One must remember that the point is too warm the strainer-not to make it too hot to touch. The paint should not be discolored. On the other hand if I was teaching beginners I probably would not go into it.

As to putting a torch to a cylinder-NO!
Nh3 is almost always charged as a liquid. There is no need to heat the cylinder unless it has been in a cold environment. If I was to do this I would use warm water-with appropriate caution.
Having been in the vicinity of a split cylinder years ago, I do not wish to repeat the experience.

One must remember that what a experienced mechanic may do is what may get a less experienced one into a great deal of difficulty.

[brunstar]

yes as the previous post stated, we have all heated a gas bottle with a naked flame but it must be evenly applied around the bottle.

I would not recomend it though, but i would recomend a refrigerant bottle blanket which is similar to your electric blanket but it is designed for gas bottles being the safer option.. cheaper to run than an oxy accetalyn rig also..
SAFETY SAFETY SAFETY!!

[Grizzly]

Just to clarify.
I did not realise how my post actually read.
I have never applied a naked flame to a cylinder.
And never would.
But I have applied a flame to the crankcase of a large 12 cylinder recip, when say the evap fans have failed and the crankcase has filled up with liquid refrigerant mixed into the oil,
For example.
As for using Oxy acetylene you would have to be mad.
By naked flame I mean a butane / propane style torch or something similar with a gentle flame.
Grizzly

[VGV]

Thanks for the input.

VGV

[PaulZ]

I have used heat on strainers and pipework to get rid of the NH3, Mapp gas torch or halide lamp. As stated by NH3LVR, NH3 is charged as a liquid if the conditions are very cold warm water only, never an oxy. If I have had a crankcase full of liquid I have used an oxy but very carefully, a heater is better and safer plus the paint doesn't get damaged.
Paul

[ART KUHN]

There are plenty of situations where you need to heat up things including amonia bottles.It is the question how far can you go?I have no idea.When i had to charge a co2 system with an evaporating temp -2 degrees with a outdoor temp 0 dergrees but the engine room 4 meters high and the cylinder at ground level i had to heat it up.Open fire was the only optionthe only hot air i had was a paint stripper 2kW.I think that there is no problem as long as you know what you are doing and the paint on the cylinder as spoken of before is a very good point to watch carefully.

Regards Art

[brunstar]

yeah as long as the heat is applied evenly and not concentrated in the one spot and you watch the bottle pressure on your guages. gas bottle electric blanket is safest..

[Grizzly]

Nobody seems to of mentioned the old fashioned method of using a bucket of hot water?
Grizzly

[NH3LVR]

Nobody seems to of mentioned the old fashioned method of using a bucket of hot water?
Grizzly
I did-but it has to be a big bucket.:D

[josef]

Hi, water is water

[ART KUHN]

Most chemicel plants all have steam outlets that is better i think

[Grizzly]

Most chemicel plants all have steam outlets that is better i think

I work with both mediums, I am not prepared to mix them!
Grizzly:eek:

[brunstar]

yeah in Oz i have used the pressure relief valve on the domestic hot water cylinders but learnt from that as sometimes they don't seat again and you have to tell the end user their pressure relief is leaking.
One good thing about liquid charging now is that most of the time unless you have left the bottle outside you are generally safe, unlike charging vapour ie:R22