Application area
Mechanical overpressure protection devices with built-in directional discharge pipe. Provides pressure relief and storage of insulating fluid (requires additional piping) on transformers and transformer winding tap changers when overpressure conditions occur. Automatically restores seal after pressure release.
Used to provide maximum critical overpressure protection on critical oil-filled transformers, load winding switches and other liquid-filled equipment.
Advantages:
- 50% percent better transformer protection at critical overpressures
- Less impact on the environment and less cleanup work
- Protect workers and equipment from hazardous oil spills
- Corrosion resistant design
- Wide range of installation options
Possibilities:
- Double spring valve ensures precise actuation and re-closing after pressure situation
- 50% higher flow rate than LPRD to increase tank protection during overpressure situations (12600 SCFM)
- Uses the same bolt pattern as LPRD and industry standards allowing direct replacement
- Standard built-in guard with 8" outlet diameter for fastest, targeted release of hot oil and gas
- Reduces risk to the environment, surrounding assets and people in the immediate area when used in conjunction with piping kits
- A variety of optional piping, flange and animal screen kits are available from Qualitrol for hot oil drainage
Options:
- Operating pressure, seal material and indicator type
- Up to 2 latching or momentary switches (single or double pole Form C, high DC or low current contacts)
- Electrical connector type
- Gas release system
- Stainless steel piping and housing options
Specifications | ||
Dimensions | Recommended tank opening | 171.5 mm [6.75 in] |
Casing bending radius: | 323.3 mm [12.73 in] | |
Electrical parameters | Switch options | Standard – 10 A at 125/250 VAC |
Non-inductive – 0.5 A at 125 VDC | ||
Non-inductive – 0.25 A at 250 VDC | ||
High Current (SPDT only): 10 A at 125 VDC (DC) | ||
Low Level Circuits (Gold Contacts): 0.1 A at 125 VAC | ||
DPDT Switch: 10 A @ 125/250 VAC; 0.5 A at 125 VDC, non-inductive; 0.25 A at 250 VDC, non-inductive; 0.25 A at 250 V (DC), non-inductive | ||
Dielectric strength | AC 2000V, 50/60Hz for 1 minute | |
Working conditions | Working temperature | -40 to 80°C (-40 to 176°C) at 30°C ambient oil temperature |
Salt chamber test | The materials and coating have withstood 1,000 hours of salt chamber testing per ASTM B:117 without noticeable loss of strength in any structural members | |
Switch housing | Meets IP54 requirements | |
Materials | Basic flange | Die-cast aluminum, light gray powder coated ASA 70 |
Ring | Aluminum casting, ground conversion coating | |
Valve | Stainless steel, seal areas lubricated with silicone-based lubricant | |
Indicator (semaphore) | Aluminum with nylon or epoxy/polyester coating | |
Spring | ASTM A229 Oil Tempered Spring Wire, Epoxy/Polyester Coated | |
Seals | Nitrile (standard) or Viton (optional) | |
Casing/housing | Stainless steel | |
Signal contact block housing | Die-cast aluminum with polyester powder coating | |
Pressure Relief Characteristic | Bandwidth | 356.8 m3 per minute at a pressure of 1.05 atm., operating pressure 0.7 atm. |