regulator selection and setup.

[1carwash1]

I'm rebuilding a pumping plant and remembered in another post that the regulator bypass should be plumbed on the same side of the pump head. In the picture shown, it shows the inlet on the left and the bypass return on the right. Is this wrong?

Also, I was considering replacing all the regulators with either the BR5-2 or SMC 555 series. If I went with SMC, would it be better to use brass or stainless?
What is the difference between the 5551790 and 5551390 or should I just opt for the brass 5550090. I have always used the BR5-2 and was leaning in that direction. The regulator that came with the plant is a VRP200; it doesn't seem to be readily available. Any ideas?
Running 3HP motors & Cat 5CP2120W pumps.

 

[MEP001]

I've switched from the Paraplate BR-2 to the SMC 555 series. The SMC last just as long, and I've never seen a catastrophic failure of one. I use the brass ones (The 5550090), and I don't think I have ever replaced a bad one.

The difference in the two part numbers you posted is probably the type of o-rings, but as long as the brass ones last I wouldn't use the stainless ones.

 

[1carwash1]

I've switched from the Paraplate BR-2 to the SMC 555 series. The SMC last just as long, and I've never seen a catastrophic failure of one. I use the brass ones (The 5550090), and I don't think I have ever replaced a bad one.

The difference in the two part numbers you posted is probably the type of o-rings, but as long as the brass ones last I wouldn't use the stainless ones.

Thanks,
I would imagine that brass or ss they are physically the same size; in other words they are interchangeable.
Mep, in a previous post you weighed in on how to properly plum the discharge to minimize cavitation. The way this is plumbed now the inlet and bypass are plumbed on the opposite side of the head. is this correct?

 

[MEP001]

The bypass should go to the same port as the water inlet. I usually plug one inlet port and have only the gauge on that side. I use unions at the pump on the other side so all the plumbing can be disconnected easily and quickly.

 

[1carwash1]

The bypass should go to the same port as the water inlet. I usually plug one inlet port and have only the gauge on that side. I use unions at the pump on the other side so all the plumbing can be disconnected easily and quickly.

I have been looking at different unions, preferably stainless or brass, what unions do you use?

 

[MEP001]

Brass. I've never had an issue. Stainless has to be tightened way super tight to make it seal.