Pressure Relief & Control

Pressure Relief & Control


Insulect provides a full suite of pressure related devices, covering everything from pressure indication, control and switches, to pressure relief devices. All transformer sizes and specifications are catered for, including:


  • Pressure relief devices - XPRD, LPRD, MPRD and smaller 201/2/5 series
  • Pressure or vacuum switches, indicators and bleeders
  • Rapid pressure rise relays
Add To Cart

Complete Transformer Protection

World Leading Pressure Relief Devices

Insulect has one of the most comprehensive ranges of transformer protection and control devices available in the market. Our primary partner in this field is Qualitrol, a world leader in rugged, reliable transformer systems. We offer pressure controls, indicators, pressure relief devices (PRDs), and rapid rise relays. To find out more about asset protection, click here, or continue down to find out which device will suit your needs best.



Qualitrol XPRD Extra Large Pressure Relief Device

Mechanical over pressure protection device with integrated directional discharge outlet. Provides pressure relief and insulating fluid containment (requires optional piping) on transformers and load tap changers during over pressure conditions. Automatically reseals once pressure has fallen.

Top 5 Benefits

  • Dual spring loaded valve for quick operation and reseal after a pressure situation
  • 50% higher flowrate than the LPRD for increased tank protection during an over pressure event (12600 SCFM)
  • Utilizes the same bolt pattern as the LPRD and industry standards enabling direct replacement
  • Standard integrated directional shield with 8 inch diameter outlet to maximize flow rate and control hot oil and gas discharge
  • Reduces risk to environment, surrounding assets, and people in the immediate area when used in conjunction with piping kits



Qualitrol LPRD/208/213/216 Large Pressure Relief Device

Mechanical device for relief of excessive pressure buildup in large volumes of gas or fluid. Patented dual gasket system provides quick response time and automatically reseals after pressure has subsided. Options include local operation indication, contacts (switches) for operation alarming, and directional shield for hot oil and gas exhaust control. 

Top 5 Benefits

  • Robust design and materials provide reliable protection and long life
  • Dual gasket design provides amplified force for rapid operation
  • Patented secondary seal wiper gasket provides more reliable resealing
  • Switches can be specified to operate as latching or momentary, SPDT or DPDT, high DC, or low current gold contact type, and with connector, terminal box, or flying lead style connections
  • Device can be top mounted horizontally (recommended) or side mounted vertically for maximum installation flexibility


Qualitrol 206 MPRD Medium Pressure Relief Device

Medium Pressure Relief Device (MPRD) is designed for over-pressure conditions on oil filled transformers, load tap changers, and other related electrical apparatus.

Top 5 Benefits

  • Stainless steel shield mounted on top of device redirects flow of hot oil and gas away from personnel or critical parts on the transformer
  • Mesh flow opening allows for the quick pressure relief, protecting your equipment while limiting the possibility of debris entering the device
  • When the pressure rises rapidly above the operating pressure, the unit will exhaust with a percussive “bang”
  • Corrosion resistant materials and robust design provide dependable protection
  • Mechanically fastened dual sealing gasket eliminates the potential of seal blowout and protects against contaminants such as dirt and moisture


Qualitrol 201/202/205 Small Pressure Relief Device

Mechanical over pressure protection device provides pressure relief on transformers during over pressure conditions, automatically resealing once pressure has fallen. Available with a stainless steel pull ring to allow for manual operation. Optional port protection with cover for inhibiting matter from entering the valve body.

Top 5 Benefits

  • Rugged design provides trouble-free over pressure protection
  • Meets or exceeds industry standards
  • 10 PSIG valves comply with American National Standards (ANSI) C57.12.20.2007
  • Many sizes of valves allow for a number of installation options including retrofitting older equipment
  • Design prevents entry of contaminants

Need more Information?

Get in touch with our team today