T / M / 170 and ePRD E170SC, transformer pressure relief valves
The T, M and 170 series pressure relief valves protect the tank of an oil-filled transformer from rupture during an internal fault. The range covers sizes 50, 80, 125, 170 and 200 mm, and for smart transformers there is the digital ePRD E170SC version.
- Standard
- IEC 60076-22-1
- Types
- T, M, 170 (170SB, 170SC, 170SD); digital ePRD E170SC
- Sizes
- 50, 80, 125, 170, 200 mm (eDevice 170 mm)
- Body
- aluminum alloy
Price, availability and lead time on request. We help with analogue selection, customs clearance and delivery.
Description
An arc or short circuit inside the tank causes instant gas formation and a sharp pressure spike. The valve opens, releases the excess pressure together with some of the oil and closes again. The tank stays intact, oil does not spread across the substation, and the fire risk is lower. A mechanical indicator records the operation, and contacts send a signal to the protection circuit.
The valve size is chosen in proportion to the oil volume of the transformer, from 50 to 200 mm through 80, 125 and 170 mm. The T, M and 170 design series have the 170SB, 170SC and 170SD versions. The operating pressure setpoint is selected for the particular unit within wide limits. For digital substations the ePRD of type E170SC, 170 mm in size, is made, and it belongs to the eDevices family and the MeDICA ecosystem.
The body is cast from aluminum alloy. The cover that directs the oil discharge is made of plastic, stainless steel or aluminum depending on the model. The visual indicator is made of brass, stainless steel or seawater-resistant aluminum, with a red button on all models except the T. The seals are NBR as standard, and Viton, HNBR or FVMQ to order.
The coating is chosen by climate. For indoor and outdoor installation RAL 7032 with corrosion class C4-M is used, for coastal sites Geomet with class C5-M, and for offshore RAL 7035 with class CX. The valves comply with IEC 60076-22-1 and work at an ambient temperature from −40 to +80 °C. They are fitted to power and distribution transformers, new and upgraded, in offshore and tropical conditions. Operating pressures, contact parameters and the degree of protection for each version are given in the manufacturer's technical manual.
Technical specifications
| Standard | IEC 60076-22-1 |
|---|---|
| Types | T, M, 170 (170SB, 170SC, 170SD); digital ePRD E170SC |
| Sizes | 50, 80, 125, 170, 200 mm (eDevice 170 mm) |
| Body | aluminum alloy |
| Seals | NBR; Viton, HNBR, FVMQ to order |
| Ambient temperature | −40…+80 °C |
| Corrosion protection | C4-M (RAL 7032), C5-M (Geomet), CX (RAL 7035) |
Replacement for
no direct analog by designation; transformer pressure relief valves / explosion vent pipes (general type)
selected by purpose and main parameters, please confirm with our manager
Request a price and lead time
T / M / 170 and ePRD E170SC, transformer pressure relief valves. We reply within one business day.
Or email sales@usk.ua or call 044 339-50-20.
Customs codes
| UKTZED (Ukraine) | 8481 40 90 00 |
|---|---|
| HS, 6 digits | 8481 40 |
| CN (EU) | 8481 40 90 |
| HTSUS (USA) | 8481 40 00 00 |
| China customs tariff | 8481 40 00 00 |
Codes are for reference: the final code is determined at declaration for the specific model.
Questions and answers
How is the size of a pressure relief valve chosen?
The size is chosen in proportion to the oil volume of the transformer from the range 50, 80, 125, 170 and 200 mm. The pressure setpoint is selected for the particular unit.
Which coating is needed for an offshore transformer?
For offshore, RAL 7035 with corrosion class CX is used. For coastal sites there is Geomet with class C5-M, and for ordinary conditions RAL 7032 with class C4-M.
Which standards do the valves comply with?
The valves are made to IEC 60076-22-1. The ambient temperature is from −40 to +80 °C.
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