Valve Questions - 22" Piggable Line

[gfdoug]

I'm running in to the following problem:

I've been asked to replace the old valves on a 22" Pigable liquid line. Currently they are using 22" Slab Gate Valves and they were wanted to replace the valves with essentially the same setup.

The problem is that it seems 22" Gate valves are quite hard to find / long lead times / discontinued. This seems like a silly question: But am I able to use 24" valves in place of the 22" in some way?

The goal is total isolation and pigable.

Any other methods around this? They would certainly prefer not to have to replace the whole line, but replacing the valves is inevitable.

Thanks,

-G

 

[BigInch]

Probably you can use 24", but is the delivery of those really any faster?
22", not truly being a standard size, may be more difficult to find.
Ball valves?

you must get smarter than the software you're using.

 

[LittleInch]

Maybe, but depends on how long the valves are and how fast you can get back to 22". So long as it doesn't cove rthe full length of a vavle you should be OK, but you might then get restricted on pigs. Best to ask a pig vendor what his advice is, but pigs do traverse check valves and tees where they don't have direct contact with the wall so my gues sis that as long as it is less than 1D in length you are probably OK.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[gfdoug]

The 22" valve that is being replaced is some unknown distance off the launcher (most likely in the neighborhood of 50-100'). It's an isolation valve before the line goes off-site.

I think their preference is to use Gate valves, although one of the options we're going to present is swapping to ball valves.

 

[LittleInch]

Why not just remove the valve and put a spool piece in? Those fence isolation valves are a waste of time usually.

For info, why do these valves need replacing? Can't you repair or refurbish them?

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[gfdoug]

The only thing we know is that they have to replace the valve. They said it is entirely not functioning currently.

They requested that we replace the valve because according to the company's specs they have to have positive isolation before leaving their lease.

I'm all for just scrapping the valve and putting a spool piece, but per client's request (whether it's useful or not) they want a new valve in place of the old one.

So to answer the question: No repair, refurbish, or removal unfortunately.

I think we are going to look in to 24" gate valves since we are already order one of a different line under the same project under the same timeline.

Also, the other idea to use ball valves was nixed because they said they won't bury ball valves according to company policy. Lots of red tape with these guys.

 

[miya2014]

what is the purpose of the "pigging", when performing hydrotests you typically pig the line to get rid of the product while filling up the pipeline with water. If you can use a foam pig then your pigging vendor may be able to specify an adequate pig but if you are using hard pigs or smart pigs you may get into problems.

 

[BigInch]

or ... sometimes even getting rid of the water before filling with product.

you must get smarter than the software you're using.

 

[subchrissea]

The valve is there for a reason, probably to isolate the line for loading or unloading the pig launcher. If the valve is flanged you need to ensure you replace it with a valve the same end to end dimension.

Pigs normally require the bore size to be within +/- 5% of the pipe ID. A pipe at is termed 22 inch bore normally means 22 inch OD on large line sizes. Which means the ID will be smaller. I think it would be wise to check the true ID of the line. A 24 inch valve will have a longer end to end dimension and whilst a pig would probably go through it, there is a high probability the pig would be damaged. Certainly this would not be acceptable if using an intelligent pig. 22 inch through conduit gate valves are available albeit made to order. A ball valve is an acceptable alternative but would need to have hard seat inserts because of potential pigging damage to the seats.

Hope this helps!

 

[BigInch]

Gauging pig.
There's many kinds of pigs. Some 10" pigs will go through a 6" pipe.



you must get smarter than the software you're using.

 

[gfdoug]

We are going to talk with the client today about possible options. They've already stated that they don't like the idea of using a 24" valve and that they can't bury ball valves. This replacement is sort of like pulling teeth at this point, eventually an option will have to be decided upon.

The kicker is that they don't know the pipe grade or thickness either and thus far trying to find the information has been a hassle. My next step is carbon testing and ultrasonic testing, then contact whoever manufactures their pigs and see what they think about the change in ID/OD, etc...

Pro tip: Don't do anything in 22" - Our valve manufacturer "No Quoted" a 22" gate valve.

-G

 

[BigInch]

Don't plan on getting any reasonable answers from a client that will bury gate valves, but won't bury ball valves. There's a few disconnected neurons there. Give them a 20" and see what they do with that.

you must get smarter than the software you're using.