Short Body Check Valve

[steven17]

I need a 42 inch swing check valve for raw sewage service. Due to piping limitations, I am looking for a short body (such as wafer style) swing check valve for sewage application. Full size check valve won't fit. Any suggestions (make and model)?

 

[itascot]

Does it necessarily have to be swing check ?
Standard swing check valves for this size in wafer comfiguration (or short bodies) will be difficult to source, of course, if you pay enough, you will find someone willing to make it for you (dont know about lead times though).
Possible options are:
Combined check valve (offset butterfly style, with counter-force).
Dual disc check valve.
Both would probably be available in short body, double flanged.
Hope this can assist.
Ciao,

 

[gerhardl]

There is a third possibillity: to use a motorized knife-gate on/off valve if you are near a pumping station or an electrical outlet.

This will need time to close and will not protect you by power failure.

If you are considering this you will have to check consequences of pressure peaks if you are pumping and the pumps closes down suddenly by power failure.

You will also have to consider UPS if you need protection by power failure.

 

[steven17]

Thanks for your tips. The double disc, butterfly style, or motorized knife gate may work, but they are not quite what I am looking for in terms of reliability. The check valve should close almost instantly with the stoppage of flow to prevent reverse flow. I believe there are wafer style (short body) swing check valve manufacturers in the market, but I don't think they are proven in the raw sewage application. I am still hoping that there might be a manufacturer who has a short body swing check valve that has been successfully used in the raw sewage service.

 

[itascot]

Most swing check valve manufacturers market up-to 36", however, Bray do have this

http://www.bray.com/docs/brochures/R-3001_EN_V31_2008-11.pdf

Hope this solves the problem, or at least points you in the right direction.
Ciao,

 

[gerhardl]

One of the problems with swing-check 'dog type trap door construction' valves with wafer type building length is that they will be reduced bore and be limited in opening (bang agains pipeline 'roof'.

Better is as mentioned before doble 'butterfly' check valves, or as mentioned perhap double eccentric single butterfly with counterwieight and perhaps dampening cylinder.

This will be the nearest you can come a full opening with a short building length. I do not know of any other construction giving you what you want with a short building lkength.

 

[steven17]

Thanks, itascot. The Bray (Checkrite) check valve is indeed the closest I came across so far. Its web site information is useful, but it still does not provide assurance that it can be used for raw sewage that carries a lot of solids (debris, rags, etc.) that could interfere with the internal shaft spring. Conventional full body check valves (without shaft spring) have been commonly used for raw sewage service without problems.

Is there anyone who have used this valve (Bray Checkrite)in raw sewage pumping stations?

I believe the double door (butterfly type) check valve is not designed to be used for sewage service. So, I am hesitant to try it unless the manufacturer would provide assurance.

A Cv value of approximately 30000 for the 42 inch check valve would suffice my needs. Normal full body check valve would have Cv value of over 40000.

 

[QualityTime]

Can you pipe the pump discharge directly to a channel above the water line and do away with any shared pipe header. This is commonly done. Putting in double door check valves etc will get you into trouble

 

[steven17]

Rerouting the pump discharge pipe to a channel above the waterline is not a viable option at this existing facility.
I am still looking for user references based on the short body wafer style swing check valve.

 

[pennpiper]

You may have better luck with a "Rubber Duckbill Check Valve"

http://www.vernay.com/ProductCategories/Duckbills.html

 

[QualityTime]

Can you reorient the pump so that you can install a proper swing check valve?

 

[steven17]

The Rubber Duckbill check valve is not the one we are looking for. We need a check valve with open/close limit switches.

Yes, reorienting the pump is an option, but it needs a lot of extra costly piping modifications, which we want to avoid if possible.

 

[QualityTime]

Under normal circumstances the check valve and the isolation valve is located at the pump discharge. It does not have to be located there. It can be further downstream and you may be able to do it be basically putting in some more extraneous piping

 

[QualityTime]

I think you are SOL. Why do you want to force an installation to be "non standard"....it is your client's money....it is not your money. If it does not work...you look bad. If I was a businessman I would be looking at desiging and installing something that i know that works. I would be assured of an in and out project without having to be called back at my own cost to explain why they are having problems. When things don't work client's have short memories of the decisions that were made.

 

[steven17]

If I were looking for a standard, common sense engineering, I would not have asked for tips in this forum. I am just looking for ideas and experiences of other engineers who might have better suggestions. I appreciate your advice, which I will keep in mind.