Packing Gland Adjustment at site (Oil&Gas Refinery)

[yldrmkara]

Is there a procedure for tightening the packing,Gland packing at valves in the field? For exampe If there is a leak, how to tighten the stuffing in the field. Is there a follow-up on how many times the packing will be tightened?

 

[mk3223]

May contact the Vendor for specific procedure. I believe it is a limit turns to tighten the packing gland of the valve.
Be caution with a safety procedure if plan to adjust it on the live line.

Or, may consider a temporary leak seal repair for it if needed.

 

[TugboatEng]

I wouldn't adjust packing on a valve in service. You might be tempted to use the back seat to isolate the packing but API feels that is not good practice.

API 589, “Valve Inspection &
Testing” section 6.2.3, states
“the successful completion of
the backseat test shall not be
construed as recommendation
by the valve manufacturer that,
while the valve is pressurized, the
valve may be repacked or packing
may be replaced.”.

As for how often the packing can be drawn up? The easy answer is until the follower bottoms out. I also feel a packing should be condemned if it has to be so tight that it impairs the free movement of the valve. Overly tight packing also increases wear on the valve stem causing increased repair costs.

 

[KevinNZ]

What you can do may depend on the process fluid. Hazardous fluid you may have to have shut to replace the packing, But cold water could allow the packing to replaced with the back seat.

 

[bcd]

No mention of valve manufacturer or type, yet responses are talking about back seating. We have no idea if there is a back seat at all. Who knows if there is really adjustable packing on the valve. OP could be looking at various components around the stem and thinks its adjustable.

Please contact the manufacturer or their designated representative in your area and get a direct reply; including any safety precautions to take. Your answer may be as simple as finding repair and maintenance instructions from the manufacturer for the valve you have on the internet. Although intended to be helpful, you have no idea if the information being provided is relevant or safe to do.

 

[LittleInch]

Some packing / stem seals you can adjust or tighten, some you can't.

A spanner usually works. If you can't tighten it any more using a small spanner and moderate force then you need to isolate to remove and replace the packing. Doing that "live" is a high hazard activity with plenty to go wrong.



Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Danlap]

It is a loose interpretation that you have to define or tune by yourself. Below is my experiences.
My sites has more than 1 million valve with various ages (1 week to 40 years old), various brand (some already obsolete), 60% of those valves are with graphite (maybe some still asbestos) gland and with various condition (good/new, fair, bad condition). I think we had around 80-100 record-able, more than 1 ppm (gas) or 1 kg but less than 10 kg (liquid) leakage per yaer.
What I proposed is to do quarter turn tightening on gland every 4 years. And for valves above 300 degC to do extra quarter turn tightening after cold situation (newly installed, after shut down)

PREVENTIVE ACTION
I did some campaign to several stake holders and multi discipline with following summary:
a.Tighten able valve is only Gate and Globe. NOT TO TOUCH Ball and Plug valve simply because they use PTFE packing, and it might be ‘crushed’ due to over-tightening
b.Segregate field team into three: common operator (they operate valves every day), maintenance team (have better understanding of gland and torque) and fire fighter team along with valve specialists.
c.Segregate valve condition into three: Good, fair, bad.
Good: acceptable rust condition, thread still ok, sufficient remaining gland bolts length for tightening, no leak
Fair: minimum to no leak, if there is a leak it should be non-very toxic medium, thread and gland flange are fair (might be slightly tilted is ok), minimum but there is still bolts length
Bad: minimum to big active leak, no thread remaining, gland flange not align, thread worn out, etc.
Note: I prepared pocket size quick reference guide with pictures for each condition.
d.Prepare general training for operator for them to identify types of manual valves (Globe, gate), and valve condition.
Note: not to touch control valve as gland torque indeed manufacturer specific.
e.Color coding with tie-wrap per year, according to maritime standard color, so it will not be re-tightened again until the next years.
f.Convince stake holders that:
-It is safe.
-Torque value might not be applicable. As this practice might be limited due to the fact that bolts are rusty, already reach bottom of thread, torque wrench is a luxury item for some production unit.
-Operator to tackle good and fair condition valve every 4 years
-Maintenance to tackle fair and bad condition valve every 4 years
-Fire fighter to tackle live leaking condition.

Wont provide details, but reason for:
300 degC --> all graphite packing consist of residue which bonds graphite together. This residue are mainly Zinc and PTFE which are malleable after 250oC (conservative number)
4 years --> friction (opening/closing) valve will deteriorate gland stress. Let say 400 cycles is the statistical number before leaks begin to penetrate bottom first gland (out of 5 rings). And valve operated 100x per year.
Quarter turn (in Dutch: kwartslaag) --> so we know that gland flange is moving down. Justification for example we may apply 25 Nm for corroded gland bolts 1”-150# gate valve. torque spanner might ‘click’ but most likely it will not even rotate due to corrosion. Plus quarter turn is ALARP in harming valve.

Outcome after 2 year implementation:
-A lot of questions and challenge to me
-Sense of ownership by operator
-Recordable gland leakage is reduced to 30-50 reports per year.

OEM SPECIFIC TORQUE
Just simply apply specific torque periodically as per OEM

Excessive leakage due to blow out, etc.
Fire fighter or maintenance tighten gland up to a point where leak stops. if not possible than isolate the line.

Regards,
MR

https://nosuchvalve.com

All valves will last for years, except the ones that were poorly manufactured; are still wrongly operated and or were wrongly selected

http://www.eng-tips.com/faqs.cfm?&rat1=2&fid=376

 

[yldrmkara]

Thank you so much Mr @Danlap and Everyone