Blackmer Bypass Values

Blackmer differential bypass valves are designed to protect pumps and system components from excessive pressure damage, and no LP-gas pump installation is complete without one. Blackmer offers five different models that provide full-flow pressure control to 250 US gpm (946 lpm) at 120 psid (827 kPa). Installation id easy with NPT tapped ports in sizes from 3/4" to 2". All models are suitable for both LP-gas and anhydrous ammonia service.

In operation, Blackmer valves provide exceptionally close pressure control, even under widely varying bypass flow conditions. A Blackmer valve maintains a virtually constant pressure of 100 psi (689 kPa) even as the volume being bypassed rises from 10 gpm to 100 gpm (38-378 lpm). Although the curve is that of a BV1-1/2" valve, the precision it demonstrates is typical of any Blackmer valve.

Blackmer bypass valves have no small, easily plugged, sensing passages; and with only two moving parts, their operation is simple and reliable. They open precisely at the preset spring pressure, and they close smoothly and quietly, thanks to a patented dash-pot design. A small chamber in the valve stem fills with liquid when the valve opens. This liquid then provides a hydraulic cushion preventing the valve from slamming shut if pressure is suddenly released. It also minimizes chatter and valve seat wear when pressures hover around the critical limit.