The water pressure regulator installed at my house is leaking thru a small hole located in front of the bell housing next to an adjustment bolt when the water is used. This water pressure unit is old, and I guess its model is Wilkens 70. I did check the new Wilkens water pressure model 70 at Home depot, and there is no small hole on its bell housing. What is the purpose of this small hole, and why it is only leaking when the water is used. Please give me an advise. Could it be repairable by installing the repair kit.

 

I'll try to explain the hole. This probably applies to your reducing valve (aka regulator). The hole probably has two purposes: 1 it is a vent; and 2 it indicates that the diaphram in the reducing valve is bad. The adj. screw on top pushes on a spring which pushes on a diaphram, and the diaphram operates the valve. Downstream water pressure pushes on the other side of the diaphram. If there is less downstream water pressure than pressure caused by the spring the valve opens. The adj. screw increases the spring pressure. The area with the spring is filled with atmospheric air. If it was not vented, the regulated water pressure would change with a change in temperature as the air inside expanded or contracted. Some reducing valves vent through the adj. screw. Some operate a little differently. I hope this was clear enough to explain the purpose of the hole and doesn't confuse you.

The water is leaking past the diaphram. My guess is that water may soon be leaking more from that hole and leaking all of the time. I don't work with that stuff enough to reccommend repairing or replacing the valve.

Phil H

 

Great explanation Phil. I enjoyed your post.