puddle flange in a manhole having a gate valve

[Bobbyvishal]

Hello,

Am I right in guessing that the puddle flange must be placed before a gate valve only and in the direction of flow. Is it important that the puddle be a double flange galvanised steel pipe with puddle flange (integral piece) or can we used simply a slide on puddle that not steel.

Thanks for helping me

 

[dicksewerrat]

explain 'puddle flange' please.

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com

 

[rconner]

I believe "puddle flange" is European terminology (the first references I can remember seeing were in British publications many decades ago) for variously constructed and manufactured raised collars or abutments placed not right on the factory ends, but instead some prescribed distance up on the barrel of pipes or fittings. These collars are at times integrally cast or formed with the item, welded onto the parent piping, or even over the years have been attached to pipes or fittings by multiple other means. Most often I believe these collars or sort of non-end flanges are (along with a short section of the parent piping) eventually formed/poured in the field by the constructor into concrete walls. The functions of the most often supplied/applied puddle flanges are probably at least two-fold:

1. For Thrust Restraint purposes (i.e. to transfer any pipeline otherwise unbalanced thrusts, from whatever source, to the concrete or reinforced concrete in which they are embedded, and thereon to the bearing and/or friction strength of the soil the concrete walls contact, with minimal movement of the valves etc).
2. Along with reasonable concrete pouring quality, for Waterstop purposes (i.e. to provide a some longer and more tortuous path for ground or tank water to penetrate from one side of the wall to the other where it is not wanted or needed, than if only a short length of pipe barrel was encased in the wall etc)

There are also such things as "loose puddle flanges", which are a different animal and intended primarily not for thrust but as a waterstop or weep ring only, and in and of themselves may not provide any or as dependable thrust restraint once poured within a wall.

The USA counterparts of European puddle flanges are generally referred to as wall collars, water stops or thrust collars etc.

As to your question is location or number of collars i.e. conclusively defined by direction of flow at a valve location, I don't think they are not necessarily so related. That being said, however, one bi-directional thrust collar along with a short length of strong pipe between and a flanged or restrained joint connection to the valve (on the end of that pipe) and a suitably, bi-directionally strong wall/soil anchorage can withstand otherwise unbalanced thrust e.g. e.g. at least due to differential pressure across a valve disk, be that load applied on either side of a close isolation or throttled valve disc at any time in test or service. You should probably check with the designer and available vendor(s) as to the intent and capabilities of their collars, and also check its/their location with exactly what the designer is wanting to accomplish with the "puddle flanges" involved.

 

[bimr]

An earlier puddle flange discussion:

http://www.eng-tips.com/viewthread.cfm?qid=121688