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Blak Jak valve covers (failures)
27 December 2018
Seasons greetings!

Has anybody experienced multiple failures in the seals for NOV 14-P-220 Valve Cap?

In the last few days, we have had double digit failures resulting in much lost drilling time as well as a messy pump room. 

The issue seems to revolve around the seal, within a short time of the tell-tale showing, mud is blowing up though the cap. I have not experienced this before, but I am unfamiliar with the Blak JAK system, so unsure if this is normal; certainly on the old-style caps, mud only came through the port.

When pulled the seals are not aways cut, which leads me to think is the torque - correct?

In summary: valve caps are leaking on a frequent basis, mud is not high temp and the majority of the failures have been on the suction side, many of the seals display no damage?

Has anyone had a similair experience? If so, how was it resolved

5 answer(s)
Shane Harper
Performance Coach
Relentless Pursuit Of Perfection Ltd.
Total Posts: 4
Join Date: 14/10/18
Cheers Scott


Note from moderator: 

I'm sure that Shane and/or his colleagues will report back the they have gotten to the root cause of this.

C'mon you lot, I know it's the Festive Season, but I would hope to read back more responses from our 2500++ members.
Shane Harper
Performance Coach
Relentless Pursuit Of Perfection Ltd.
Total Posts: 4
Join Date: 14/10/18
Thanks Paul, appreciated 


Notes from moderator:

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Consultant [retired Shell staff]
Total Posts: 248
Join Date: 02/09/05

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Total Posts: 113
Join Date: 05/03/08
Hi Shane,

Paul has pretty much covered what I was going to say already - at first glance I agree that the most likely cause is a bad batch of seals.

Going further, are all the seals from the same batch? If so, are seals from another batch available?

Also, I'm not familiar with the Blak Jak system, but have you dimension checked the seals before and after, in case some adverse reaction with the mud is causing the seal to shrink a little?

In the meantime, I wish all on SPREAD a safe, happy and prosperous 2019!

All the best

Total Posts: 91
Join Date: 10/04/08
Shane, I am not very familiar with this pump or this particular bolting locking system, but I just looked on the NOV site and saw that this pump type/style has some engineering up-date documents that tell about new part numbers for some of the parts in the pump. This leads me to suspect that some changes were made at some point to the parts or the seals. I would first of all double check the documents on this site especially to see if any parts around the seal area changed, maybe even the seals themselves. I suspect if the pumps have worked fine before its likely that some wrong seals have been used, older style seals, perhaps even some non-OEM parts have crept into the system. The link below directs you to some of the docs that might be helpful.
Posted by

Shane Harper

Performance Coach

Relentless Pursuit Of Perfection Ltd.

Total Posts: 4
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