Wilkins/Zurn Water Pressure Reducing Valve Problem

[Bob Knauff]

I have a Wilkins Mdl. 70 water pressure reducing valve on a 1" copper main line that, when adjusted in either direction by of use the diaphragm bolt, has no affect on the water pressure of 100 lb. as read with a Watts water pressure gauge at the washing machine faucet. Valve is about 10 years old.

Turning the bolt counter clockwise is supposed to reduce line pressure and clockwise, increase it. From turned all the way in to so far out it almost falls out of the housing, the adjustment bolt has no affect.

After each adjustment attempt, a house faucet is opened momentarily to allow pressures to equalize.

Any insight to potential valve problems? If found to be defective, would re-building it be adequate or is replacing the entire unit recommended.

[James Duffin]

If it does not have stainer in front of it (and it probably does not) then is full of gunk. The ones I have taken apart are in such bad condition on the insides it is easier to replace them than to rebuild it and then get it to work properly. If you do replace it be sure to install a strainer on the inlet side to keep it from happening again.

[Bob Knauff]

By gunked up, do you mean the inside of the valve housing gets messed up/damaged as well as the cartridge and/or mechanism, James?

[James Duffin]

The ones I have seen have an oily, muddy substance along with some corrosion and pitting that prevents the inside components from moving.

[Bob Knauff]

Thanks for the response Jim. I have removed the old unit and the following images are of the insides of it. I tossed the spring before I thought to take pics but it looked fine except for a whitish powdery substance on it similar to that on the rubber valve in the attached photo.

Everything seemed clean and moving freely. The only suspicious thing I noticed is the off center indent in the rubber stopper as seen in the photo. Perhaps the valve body was hitting the metal at the rubber stopper preventing it from closing all the way? I don't know. The replacement valve works fine!