FES R series

[CanadianIce]

Hi guys

I got an old FES 235 R series compressor coming in for an overhaul. Would anyone have a manual for this machine?

Thanks
C Ice

[CanadianIce]

It turns out that the information I got on this machine was wrong. The compressor is a Howden XRV 204/110, which I had a manual for.

The complaint from the customer was that the machine was noisy and wouldn't unload. Pulled the compressor apart, all the bearing clearances were good but the slide valve showed some wear. When I pulled the rotors, the tip seals were worn off by the slide valve and after reinserting the slide valve into its bore, I could see there was about .050" worn off the surface. This compressor allows the slide valve to float freely without a guide block. It appears that once the slide valve started to wear, the oil pressure pushed up from below causing the remainder of the damage. The compressor couldn't unload because the slide valve was jamming against the axial port at the outlet end. I have heard of this problem with Frick compressors but haven't run into it until now on this Howden. This must be a result of the floating slide valve rotating slightly in the bore. Any thoughts?

C Ice

[RANGER1]

It seems to be a wear characteristic with this style of slide valve / port .

I thought it might be because of frequent slide valve hunting but not convinced .

Have seen it on Kobelco , Frick and Mycom , but Mycom have Vi adjusting rod to help prevent rotation of slide .

Even with the old style guide block & pin you get wear nearly always on one side .

Have had success with repairs , what will you do ?

[Josip]

Hi, C Ice

It turns out that the information I got on this machine was wrong. The compressor is a Howden XRV 204/110, which I had a manual for.

The complaint from the customer was that the machine was noisy and wouldn't unload. Pulled the compressor apart, all the bearing clearances were good but the slide valve showed some wear. When I pulled the rotors, the tip seals were worn off by the slide valve and after reinserting the slide valve into its bore, I could see there was about .050" worn off the surface. This compressor allows the slide valve to float freely without a guide block. It appears that once the slide valve started to wear, the oil pressure pushed up from below causing the remainder of the damage. The compressor couldn't unload because the slide valve was jamming against the axial port at the outlet end. I have heard of this problem with Frick compressors but haven't run into it until now on this Howden. This must be a result of the floating slide valve rotating slightly in the bore. Any thoughts?

C Ice

it is possible to have increased noise at some capacity (due to worn slide and housing) ... I had that with VRW 163 in Arabia, but without problem related to capacity change ....

-received answer from Howden representative ... this noise is coming from flickering capacity slide due to worn condition ... maybe need to change the guide block

-- regarding problem with unloading - XRV compressor's slide is with spring ...

- there can be something wrong with solenoid valve for unloading ... maybe clogged, maybe too small etc..

-maybe you have a leak on loading solenoid valve, thus no way to unload compressor with spring because you still have a lot of oil coming into cylinder and not possible to drain it

-or worn seals within actuator cylinder and piston

-or maybe too low pressure difference (high suction pressure and low discharge pressure) in conjunction with some jamming ... sometimes is necessary to connect the drain pipe from cylinder to suction pipework

Those are some ideas ... my two cents no have experience with XRV and I can be wrong

Best regards, Josip

[CanadianIce]

Thanks for the input guys.

Like you mentioned Ranger1, I usually see a wear pattern on one side of the slide valve due to rotation in the bore, even on machines that have a guide block. I would expect to see some wear on the lower periphery of the slide valve if there was hunting but there was't any there, only the cusps were worn. This is a base load compressor so it runs fully loaded during production, then it is shut off when production is finished. I imagine the customer will opt for repair rather than replace.

C Ice

[Gerben]

Hello Canadian Ice,

the XRV204's slide actuator pistons have too large holes for the shaft, which results in bad mounting of the piston. Make sure that the shaft is really in the middle of yhe hole, in other cases the capacity goes up and the piston is stuck. The damage on the spot where the slide valve is kept in place (discharge housing) may not be such a problem.

Good luck, Gerben