The Qualitrol 900/910 Rapid Pressure Rise Relay (RPRR) is a mechanical device designed to detect sudden pressure increases in transformers and other electrical equipment. It monitors the rate of pressure rise against safe limits defined by transformer manufacturers and activates an alarm or trip signal to prevent tank damage. The 900 series is calibrated for oil-filled transformers, while the 910 series is optimized for gas-insulated applications.
 
Detects dangerous pressure rise based on rate, not absolute pressure
Will not actuate under normal pressure changes from temperature or vibration
Withstands full vacuum or up to 20 PSI without damage
100% factory calibrated and serialized for traceability
Factory tested for switch performance and response time
Field test kit available for GO/NO-GO functionality checks
Over 50 years of proven mechanical pressure protection
Bellows technology for reliable mechanical actuation
Flange or thread mounting for vertical or horizontal installation
Models calibrated for oil (900) or gas (910) transformer spaces