Hydrostatic Pressure Relief Valves

TROY VALVE has been asked many times if there is a formula to calculate sizing and placement of Tank Pressure Relief Valves. TROY VALVE has no recommended formula but can suggest some factors to keep in mind.

Hydrostatic Relief Valve installation design is entirely dependent on local conditions, structure design, draining provision, and other factors. Some factors to consider may include:

• How fast can the water table rise around an empty tank? Think of nearby rivers rising or coming through a dike. (A factor in calculating how much flow you must allow into the tank).
• How fast could you pump out a tank that had a high water table around it? (Another factor in determining inflow requirements).
• What is your drainage like around and under the tank? How easily can ground water flow to the tank relief valves? (This may influence how many valves you install. Poor drainage may allow any particular valve to drain only a small area around it).
• How strong is your structure? What is the tolerance for flotation (pipes, etc). What is buoyancy of the tank? What pressures from underneath can the floor handle without breaking?

There may be other factors to consider in designing tanks and pressure relief valves. The above is offered only as a starting point in your design considerations.

Troy valve Tank Relief Valves are very inexpensive and are a very cost effective way to protect your project. The cost of some floor or wall relief valves will be far less than the cost of losing a tank or basin.

The permanent nature of these valves should make you consider carefully the brand of valve you install. Troy Valve offers a replacement resilient seat in the lid, and a durable bronze seat in the concrete embedded body of the valve. Some valves offer only a brushed on epoxy seat in the body, leaving this embedded item vulnerable to rusting and leaking. Others offer broad faced rubber seats that do not seal well at low pressures. Specify a replaceable resilient seated lid and a bronze seat ring in the body to ensure a durable and trouble free installation. Available in 4” and 6: diameter, any length.