Overview
Regulator / bypass valve, 500 psi, for Razorback Sandia pump systems. Sandia part number 80-0016-REG.
What we can and cannot verify
We could not locate this part number in the Sandia documentation we hold. Our Sandia manual covers the 3-Gallon Spot-XTract, which runs a 55 psi pump — a different class of machine entirely. The 500 psi systems are documented separately and we do not hold those parts lists.
Send us the machine model and serial number before you order and we will confirm. It is on our list for supplier clarification.
What a regulator / bypass valve does
On a positive-displacement pump the output has to go somewhere. When the trigger is closed, the regulator opens and returns flow to the tank instead of letting pressure rise until something gives.
Two jobs in one part:
- Regulate — hold the working pressure at the set point.
- Bypass — dump excess flow when the tool is closed.
At 500 psi, this is the component standing between the pump and the rest of the plumbing.
How regulator faults present
- Pressure reads correctly at rest, collapses under trigger — worn seat or ball. The classic bypass symptom.
- Will not reach the set point at all — bypass or pump. Check the bypass first; it is cheaper to rule out.
- Pressure creeps or hunts — usually debris on the seat rather than wear.
- Cannot adjust it any more — spring or seat.
- Constant flow back to the tank with the trigger open — the valve is not closing.
Debris on the seat is the most common single cause, and it usually means an inlet strainer has been neglected. Fix the cause as well as the symptom, or you will be back.
Before you touch it
Note the pressure setting before you adjust or remove anything. It is far easier to return to a known figure than to find it again by trial, and a regulator set by guesswork on a 500 psi system is a genuine risk.
Depressurise the system before opening it.
Frequently asked questions
Which machines does it fit?
Ask us with the model and serial number — we could not confirm it against a Sandia parts list.
What is the adjustment range?
Not stated in the documentation we hold. We are not going to publish a figure we cannot verify.
Can it be rebuilt?
Not confirmed. Tell us what it is doing and we will find out before you buy a whole valve.
My pressure collapses under trigger. Is it this?
That is the classic bypass symptom — but check the inlet strainer and the jets first, because a restriction reads similarly and costs nothing to rule out.
Tell us the machine and exactly what the gauge does at rest, at trigger and on bypass, and we will help you narrow it down before you order.
