PDA

View Full Version : Howden wrv 204 mk6







GHAZ
05-06-2015, 07:03 PM
Hi friends, does anybody know what size and length bolts are needed to push of the bearings from the screws, any help would be great full, thankyou

RANGER1
05-06-2015, 10:29 PM
Hi friends, does anybody know what size and length bolts are needed to push of the bearings from the screws, any help would be great full, thankyou

Assume you are talking about thrust bearings?

Not a 100% sure, but 16mm x approx 200mm long.
Each thrust bearing about 25mm wide x 2 off them
If going on site take 12,16 & 20 mm threaded rod & nuts.

Are you replacing thrust bearings only, or removing rotors as well?
I have found on the few 204 I have done that jacking holes are part of balance piston sleeve, which when you jack the bearings of there is possibility of distorting the sleeve.
This may then give you different end clearances.
I would normally jack rotors out towards inlet end after removing inlet cover/housing.

RANGER1
05-06-2015, 10:43 PM
Older machines had UNC threads, so if you don't want any problems take that as well 1/2, 5/8, 3/4"

GHAZ
05-06-2015, 10:56 PM
Hi ranger I'm totally stripping it out, everything apart, thankyou for the advice friend

RANGER1
06-06-2015, 07:39 AM
Hi ranger I'm totally stripping it out, everything apart, thankyou for the advice friend
Have you got all the info you need, manuals etc etc, if not let me know.

GHAZ
06-06-2015, 09:51 AM
Hi ranger I have no manuals,

RANGER1
06-06-2015, 10:36 AM
I will email you can ne tomorrow

RANGER1
06-06-2015, 11:05 PM
GHAZ, sent this morning

GHAZ
07-06-2015, 09:34 AM
Thankyou friend

Tycho
08-06-2015, 08:36 PM
Assume you are talking about thrust bearings?

Not a 100% sure, but 16mm x approx 200mm long.
Each thrust bearing about 25mm wide x 2 off them
If going on site take 12,16 & 20 mm threaded rod & nuts.

Are you replacing thrust bearings only, or removing rotors as well?
I have found on the few 204 I have done that jacking holes are part of balance piston sleeve, which when you jack the bearings of there is possibility of distorting the sleeve.
This may then give you different end clearances.
I would normally jack rotors out towards inlet end after removing inlet cover/housing.

Tiny correction, the jacking holes are not on the balance piston, they are on the end clearance shim, so you have to be all the more careful if you use them to jack the bearings out.

On the MK6 it should be new enough for all threads to be millimeter, the jacking screw should go in easily without force, if you encounter abnormal resistance, try with a 5/8 threaded bar instead and see if it goes easier.

The thrust bearings are not hard to jack out on a WRV, I use two ratchets, one on each of the jacking rods so that I can assert even pressure on both jacking rods.

The bearings should come of easily, if you have to use force, something is wrong and I would consider using a central jacking screw instead.

:)

RANGER1
08-06-2015, 09:51 PM
Tiny correction, the jacking holes are not on the balance piston, they are on the end clearance shim, so you have to be all the more careful if you use them to jack the bearings out.

On the MK6 it should be new enough for all threads to be millimeter, the jacking screw should go in easily without force, if you encounter abnormal resistance, try with a 5/8 threaded bar instead and see if it goes easier.

The thrust bearings are not hard to jack out on a WRV, I use two ratchets, one on each of the jacking rods so that I can assert even pressure on both jacking rods.

The bearings should come of easily, if you have to use force, something is wrong and I would consider using a central jacking screw instead.

:)

Tyco, I wrote "balance piston sleeve" :)which has 2 lugs.
I have only done a few that size, but have found the lugs slightly bent with the pressure applied to the "ears or lugs". I see it as average design as older models were same as larger WRV.
Have used a dummy set of thrusts with inner race opened up a bit so as slip fit.
Once ok then install the new bearings in hope the clearance is ok.

Tycho
12-06-2015, 10:39 PM
Tyco, I wrote "balance piston sleeve" :)which has 2 lugs.
I have only done a few that size, but have found the lugs slightly bent with the pressure applied to the "ears or lugs". I see it as average design as older models were same as larger WRV.
Have used a dummy set of thrusts with inner race opened up a bit so as slip fit.
Once ok then install the new bearings in hope the clearance is ok.

Sorry Ranger1, I missed the sleeve part when I wrote my reply (my bad)

I've done quite a few of these and have (knock on wood) never bent any of the shims/sleeves.

The trick is to use two ratchets and apply even pressure to both at the same time, the moment you have to use force to get the thrust bearings out, something is wrong, they should only be heated to 20K above ambient before installation.
I have witnessed people jacking then out buy working on one jacking screw until it gets stuck, then moving to the other jacking screw, rinse and repeat... they were from a competing company and I was doing the refrigerant pumps or some other stuff, so I kept my mouth shut :)

we have a plane table where we check the shim/sleeve on after we get it out.

I really like working on Howden Compressors, they are well machined and if you take care of them they will last forever...

I do however hate overhauling the XRV127 with any kind of gearbox on it... XRV127 with a gearbox means dismantling it at least 4 times to get the end-play correct...


I sent GHAZ a PM with my contact info on whatsapp and viber and told him to message me if he had any questions, and I got a message from him two days ago saying:
"Hi tyco thanks for help offer, it was pretty straight forward, job, the customer was complaining about the howden 204 mk 6 being noisy and pulling over 600 amps on start up, so I took off the slide valve section and it had about 12 litres of oil come out from the crank case and I turned the screws easy by hand and then I open discharge service valve and noticed that the non return valve was letting gas by, causing the compressor to flood with oil, because the condenser is about 40 meters high,"

"

RANGER1
12-06-2015, 10:59 PM
No worries Tyco,
Good tip on jacking out bearings.
I have only done a few of WRV204 with that arrangement & found both damaged prior to me touching it because of that.
I always tend to push rotor out with these like 255 & 321
Have done the old type WRV204 which are better for adjusting end clearance.
Mae do have trouble with Howden on the newer ground rotors though, rotors appear very sensitive
& mash themselves up, reason unknown?

Tycho
13-06-2015, 12:11 AM
No worries Tyco,
Good tip on jacking out bearings.
I have only done a few of WRV204 with that arrangement & found both damaged prior to me touching it because of that.
I always tend to push rotor out with these like 255 & 321
Have done the old type WRV204 which are better for adjusting end clearance.
Mae do have trouble with Howden on the newer ground rotors though, rotors appear very sensitive
& mash themselves up, reason unknown?

I haven't seen any rotor damage on the WRV range...

But on the XRV range, where they don't have the slide valve guide block, jezzus....
when they are on a VFD *shudder* what we call "slide valve noise". 2400 rpm, as the slide valve is moving, at around 40-60% it sounds like someone threw a bucket of scrap metal into the suction.

Howden says it's the slide valve vibrating, IE rolling from side to side and touching the rotors.
On older models the wear would be on the rotors, but lately I have seen that all the wear was on the slide valve.
I opened an XRV127 3 days ago and the surface of the slide valve was worn down 2mm

I don't get why they don't implement a guide for the slide valve on the XRV range

RANGER1
13-06-2015, 04:17 AM
I haven't seen any rotor damage on the WRV range...

But on the XRV range, where they don't have the slide valve guide block, jezzus....
when they are on a VFD *shudder* what we call "slide valve noise". 2400 rpm, as the slide valve is moving, at around 40-60% it sounds like someone threw a bucket of scrap metal into the suction.

Howden says it's the slide valve vibrating, IE rolling from side to side and touching the rotors.
On older models the wear would be on the rotors, but lately I have seen that all the wear was on the slide valve.
I opened an XRV127 3 days ago and the surface of the slide valve was worn down 2mm

I don't get why they don't implement a guide for the slide valve on the XRV range

just a guess, but I thinks it's to do with money!