Gate Valve installation

[teddyboy]

Hi everyone, Could somebody give me a tip regarding the gate valves on horizontal line with its handwheel at horizontal position. If this arrange will not be of any problem in the future? The applications are for steam and liquid hydrocarbons.

 

[pennpiper]

I think you mean "The stem" in the horizontal position, right?
If so then let's look at this in a logical manner.
What if we had a Gate Valve in a vertical line? The Stem would be in the horizontal position would it not?

So if a valve stem in the horizontal position is alright for a vertical line why would a valve stem in the horizontal not be alright for a horizontal line?

 

[BigInch]

The handwheel might be buried 4 feet underground.

**********************
"Pumping systems account for nearly 20% of the world’s energy used by electric motors and 25% to 50% of the total electrical energy usage in certain industrial facilities." - DOE statistic (Note: Make that 99.99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[insult2injury]

Advise the vendor of the orientation. Often they will hardface the sliding the contact faces of the guides; otherwise, it's the same valve.

I2I

 

[JJPellin]

In the past couple of years, we have seen a growing problem with broken stems on gate valve. I think the quality of valves coming from some countries is less than it had been in the past. With the stem in the vertical, a broken stem can result in a valve failing closed. With the stem in the horizontal, the valve would tend to fail in place if the stem breaks. You should consider the consequences of these possible failure modes. In some services, a valve that failed closed unexpectedly could cause disaster. If this is the case, I prefer a horizontal stem orientation. Otherwise, it’s just a mater of convenience and operator access.

Johnny Pellin

 

[BigInch]

Interesting point, but I think, if it is truely a 50/50 position thing w/o actuator, I'd rather have a valve fail closed. At least you know you've got a problem then if you run out there during some kind of emergency and try to close it only to find out you can't.

**********************
"Pumping systems account for nearly 20% of the world’s energy used by electric motors and 25% to 50% of the total electrical energy usage in certain industrial facilities." - DOE statistic (Note: Make that 99.99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[KenA]

BigInch - just so long as that gate valve isn't in the inlet to a PSV!

 

[BigInch]

Da.

That wouldn't be one of those 50/50 situations.

**********************
"Pumping systems account for nearly 20% of the world’s energy used by electric motors and 25% to 50% of the total electrical energy usage in certain industrial facilities." - DOE statistic (Note: Make that 99.99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[gmax137]

Are you guys allowed to put gate valves at the inlet to safety valves?? Or, does "PSV" mean something else?

 

[Zapster]

gmax137, YES unless the latest edition of the BPV code has changed.

 

[Zapster]

I had to take a look at the BPV VIII Div 1 just to remember all of the nuances required for a stop valve. The current version of the code is 2007. I only have 2004 at my office and I have inserted the dialog from the 2001 version below. The 2004 goes into greater depth about the limitations; however they are still allowed. As I stated above, I am unsure about the 2007 appendix.

M-5 STOP VALVES BETWEEN PRESSURE RELIEVING DEVICE AND VESSEL
(a) A vessel, in which pressure can be generated because of service conditions, may have a full-area stop valve between it and its pressure relieving device for inspection and repair purposes only. When such a stop valve is provided, it shall be so arranged that it can be locked or sealed open, and it shall not be closed except by an authorized person who shall remain stationed there during that period of the vessel’s operation within which the valve remains closed, and who shall again lock or seal the stop valve in the open position before leaving the station.