The PRD-25 pressure safety valve is employed as a safety element in distribution transformers of low rating. In the event of an explosion-type pressure increase of the transformer tank, the excess pressure must be relieved immediately in order to avoid damage to the tank. These types are suitable for hermetically sealed type transformers.

The PRD-25 pressure safety valve consists of a brass cap, a conical valve body, a rubber seal between the cap and body and a coil spring holding the whole system. As soon as relief pressure is reached, the valve cap lifts off and the excess pressure is relieved. The valve then shuts itself down again automatically. The valve can be infinitely set from 0.2 to 0.7 bar. The valve can also be equipped with a specially manufactured protective cap to prevent unauthorized operation of valve.

The PRD-50 pressure safety valve is employed as a safety element in distribution transformers of low rating. In the event of an explosion-type pressure increase of the transformer tank, the excess pressure must be relieved immediately in order to avoid damage to the tank. These types are suitable for hermetically sealed type transformers.

The PRD-50 pressure safety valve consists of a brass cap, a conical valve body, a rubber seal between the cap and body and a coil spring holding the whole system. As soon as relief pressure is reached, the valve cap lifts off and the excess pressure is relieved. The valve then shuts itself down again automatically. The valve can be infinitely set from 0.2 to 0.7 bar. The valve can also be equipped with a specially manufactured protective cap to prevent unauthorized operation of valve.

This type of Pressure Relief Valves features a one-piece brass housing. A stainless steel spring, factory selected to a predetermined rating, is designed to release pressure build-up from within a sealed tank. A rubber O-ring seals the valve. There is a stainless steel pull ring attached to the valve shaft to allow for manual operation.

These valves are designed to operate under environmental conditions encountered on outdoor applications. The exhaust port is protected by a "bug shield" cover which inhibits foreign matter from entering the valve body. The valve setting is stamped on the "bug shield" for fast and easy identification. These types are suitable hermetically sealed type transformers.