Extended Bonnet Valves

[whatthe]

I'm working on a project that requires some 36" and 42" gate valves (low pressure, normal temp, basically water 150# service). We have to bury the lower half of the valves around 1.5m-1.8m in the ground and the client is not going to build a caisson around the valves. We want to use an extended bonnet valve in order to have a valve that can be half-buried and still keep the exposed part of stem and packing above grade.

Does anybody know if there is a manufacturer who can actually supply information on length up to the packing so we can determine suitability? Our critical height is from the valve centerline to the top of the packing and I've been having a difficult time getting this information so far. Standard catalogs tend not to cater to the extended bonnet versions.

Are there other options worth considering? I've seen some options for double shell enclosed gear extension type valves, but I'm not sure how those would be to service the packing years down the road if needed.

 

[pennpiper]

Try here and see if this will meet your needs

http://www.townofcary.org/depts/dsdept/engineering/detaildrawings/ACAD-0600019.htm

 

[Joesteam]

I have used a ball valve in this service. I have used a third party service that puts an extension on the stem nut and then puts this in a pipe. The dirt covers the pipe but not the extension. Then a mounting plate on top for a handwheel, actuator, or lever, and a mounting plate on the bottom....

Joe Lambert

http://www.control-associates.com/

 

[JimCasey]

You might want to talk with these people. They've done what you are proposing many times.

http://www.bitorq.com/extensions.html

 

[gerhardl]

1. Ask suppliers for a preliminary, technically qualifying offer. Inform about number of valves, service, technical details required, and that final inquiry and selection will be based on information received.

2. Double eccentric BFL valves with lifetime greased reduction gearbox and lifetime stem bearings suitable for burying to be considered ? Normaly cheaper than your choice. Operation aboveground by stem extension, easy to automate later. Drawback: no pigging possible. Possibly, but not necessarily, larger pressure loss (to be checked for actual valves)

 

[JLSeagull]

Several manufacturers offer shaft extensions for buried valves.

 

[NGiLuzzu]

whatthe,
why gate valves, if I may ask?
Must they be piggable?
Are quarter-turn valves allowable instead (with the same face-to-face dimensions, if necessary)?

Regards,
'NGL

 

[reverman]

Almost any gate valve manufacture will modify their existing design to meet your requirements.

Powell, Crane, Velan, Walworth, etc..


Or if you already have the valve you can send it to a valve modification shop and they will make the valve the way you want it:

United Valve, Gulf Coast Modifications, VR-Tesco, Continental field services.

to name just a few