TIVAL FF 4 DRH pressure switch - manual reset maximum protection

Mechanical pressure switch with manual reset for overpressure protection

The TIVAL FF 4 DRH combine the proven Perbunan diaphragm with a manual reset function as maximum pressure protection. With a pressure range of 0.11-32 bar and manual reset, they offer reliable monitoring for compressors and pumps with trigger protection in the event of overloads.

FF 4 DRH - Pressure switch with manual reset for fuse applications

The FF 4 DRH is a specialized safety variant of the TIVAL Pressure switch with manual reset function. Unlike standard pressure switches, the DRH locks after overpressure detection and must be reset manually - ideal for safety applications. With the familiar Perbunan diaphragm and G 3/8" silumin connection, the DRH is a reliable maximum pressure protection solution for compressors and pressure build-up systems.

Technical features & Construction

Like the DAH(G), the FF 4 DRH has a Perbunan diaphragm with a direct switching mechanism. The additional feature is a manual reset mechanism - after triggering in the event of overpressure, the operator must reset it manually. The housing is made of die-cast silumin with IP54-65 protection. The connection thread is G 3/8" made of silumin. The pressure range is infinitely variable from 0.11 to 32 bar, identical to DAH(G). The switch contacts are standard contacts.

Pressure ranges & areas of application

The FF 4 DRH is particularly suitable for safety applications where a manual reset is required - such as compressor maximum pressure protection or pump overpressure protection. The pressure range 0.11-32 bar covers the low pressure range as well as DAH(G). The low response pressure of 0.11 bar allows precise switching thresholds. The versatility (oil, water, air) is identical to DAH(G). The manual reset safety concept makes the DRH a special solution for process-safe applications.

Standards & approvals

The FF 4 DRH complies with VDE 0660, IEC 337-1 and IEC 553-1 standards like all FF 4 variants. The manual reset function is certified as a safety feature. With an IP54-65 protection rating, the pressure switch offers protection in industrial environments. EN 60947-5-5 electrical switch certification is available. The safety release function is taken into account in machine safety guidelines.

DRH vs. standard variants

While DAH(G) automatically relocks when overpressure is detected, DRH remains locked until manually reset - this is the safety advantage. DRH has identical diaphragm technology and pressure ranges as DAH(G), but differs in the reset concept. DRH is not suitable for continuous switching, but for safety applications. For standard operation, select DAH(G); for safety and process safety, select DRH.