DANIEL V707 User Manual page 11

Introduction
August 2019
bottom side of the piston. The pressure at the bottom side of the piston must exceed the
spring force to unseat the piston and open the valve.
An adjustment mechanism provides a means to adjust the spring load in the back of the
piston, which adjusts the valve opening pressure within the spring's pressure range or set
point range. The 707 springs are a nested design; this allows two springs to be combine for
rd
3 set point which is an extension of the first two. The designed set point ranges for the
707 springs are as follow.
707 Springs
Light
Medium
Combined
Once the operating pressure or set point is reached, the valves opens and begins to flow.
The 707 has a balanced piston design, which means that the spring force on the spring
side of the piston must be equal or greater than the pressure at the bottom side for the
valve to remain closed.
Closed position
Figure 1-1 illustrates a closed valve. The pressure at the bottom side of the piston P1 is less
than the spring force F1 plus the check line pressure the P2. The piston is kept seated and
the valve remains closed.
Figure 1-1: Valve in closed position
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Set-point range (Psig)
5 to 40
30 to 80
30 to 120
707 Spring Loaded Back Pressure Valve
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USER MANUAL
User manual
DAN-20064957
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