High Temperature Trip Valve Natural Gas Air Pneumatic Valve Emerson Fisher 377 Pressure Sensing Trip Valve

The red box that opens the recycle valve in 1 second when the DCS dies

Modern anti-surge systems have triple-redundant solenoids and fast controllers, but the last backup is always a Fisher 377. If the instrument air drops or the signal disappears, the 377 sees it instantly and dumps air from the actuator – recycle valve slams open, compressor never surges. No electricity needed, no software bugs, just pure pneumatic speed. Refineries and LNG plants won’t start the machine without one.

• 3/4" ports and huge Cv – vents even the biggest actuators in 1–2 seconds
• Factory set to trip at 25–30 psi – perfect for most surge systems
• Three independent diaphragms – two can fail and it still trips
• Stainless tag with trip point engraved
• Test button right on the side – push and watch valve open

• Cracker gas compressors
• Refrigeration compressors in LNG
• Centrifugal air compressors
• Pipeline booster stations

Q: Can I test it without shutting down?
A: Yes – push the red button, valve opens, compressor stays online.

Q: Do I need volume boosters?
A: Usually not – the 377 vents fast enough by itself.

Phone: +8615000725058
Email: edwardzhao@gbsxj.com

• Fisher 377L – lock-up version (holds position)
• Fisher 377D – dump on low signal only
• Fisher 377U – dump on high signal