Valve to throttle flow in a force main

[jartgo]

I have a grinder pump station where an automatic sampler will be required to sample the effluent from the station. Since the sampler needs "non pressurized" flow and a stream of about 15gpm, the manufacturer's rep has recommended a loop be constructed immediately at the start of the force main.

It's a 3-inch force main and the loop will be a 1.5 inch PVC going right back into the wetwell, which will be throttled through the use of a valve to achieve the desired 15gpm. The manufacturer's rep has recommended just using a pvc ball valve in this case, but I'm not sure what other options I might have. Normally we wouldn't use a ball valve in wastewater applications but perhaps it's OK on a bypass loop such as this?

 

[semo]

Why not put the sampler at the discharge location? You can drop it down the manhole or whereever the forcemain ends.

I wouldn't be really keen on making a bypass loop like you are talking. 15gpm bypass will really hurt the efficiency of your grinder pump.

 

[bimr]

Why don't you just get a sampler that can do the job. This model can take a sample from a pressurized line:

http://www.bvssamplers.com/BVS_Info.pdf

 

[jartgo]

semo, the reasons for not sampling at the discharge location are that it's three miles from the project site, and the discharge is mixed with other wastes.

bimr, I spoke with the folks at BVS, sounds like this is another option, albeit more expensive. Options are always good...thanks!