CRUDE OIL PUMP SEAL LEAKAGE

[shyamshins]

Dear sir,

I am facing leakage problem with single seal installed on pump used to pump CRUDE OIL.

Leakage is observed from Gland Gasket Part.no G (O ring between stuffing box & seal gland ring.

Customer has not provided API Plan 13 for flushing.They are adding D emulsifier for removing water from crude oil & Descalant to avoid formation of scales in pipe line. This problem has started when they started adding d emulsifier & descalant to Crude oil before addition of d emulsifier & descalant to crude oil pump used to run successfully but customer is not agreeing.I checked O ring gland gasket(MOC VI TON) for deformation, swelling or chemical attack but no evidence was found.

My boss is asking to increase thickness of O ring (Part no.G)to stop leakage.What could be possible cause of leakage? Pls. help.

 

[JJPellin]

There are three other o-rings in this assembly. If the gland gasket is Viton, I would assume that the other three are also Viton. If the only leakage is the gland gasket, then I would not expect a material compatibility problem. A static o-ring seal should not leak if it has an o-ring groove of the proper dimensions, the correct amount of crush and the proper surface finish. First, I would verify all of these. Simply making the o-ring fatter (larger cross-section) does not feel like a good solution. If I was going to redesign this gasket, I would convert to a spiral-wound gasket. It would cost a little bit more, but would be more forgiving.

Johnny Pellin

 

[flexibox]

Looking at the seal drawing it seems that this is an existing design not new. If it is leaking from the Gland Gasket then something has changed; check the following: 1) It looks like a 3.53 sect oring depth of groove should be 3.0/3.1mm 4.5 wide groove. It looks like there is a cooling or heating jacket in stuffing box, is surface distorted? Agree with Johnny that increasing Oring section will not solve the problem and if Oring material is OK for other positions then compatibility does not seem to be the problem. are you sure that the leak is from the gland plate gasket? Is it running down the drain connection meaning a face leak? Thats what I suspect! have a close look.