MPC1-1000 and MPC1-3000 User’s Manual
3.3
SETTING POSITIVE GAUGE PRESSURE (ABOVE ATMOSPHERE)
All of the following procedures instruct the operator to open the equalization valve prior to opening
the test inlet and outlet valves. THIS IS A SAFETY PRECAUTION.
It is possible to adjust the pressure in the test circuit using the test inlet valve without opening the
equalization valve. However, this should be done ONLY WHEN THE OPERATION OF THE
SYSTEM AND THE CONSEQUENCES ARE UNDERSTOOD BY THE OPERATOR. Refer to
Sections 3.1, 6.1 and 6.2 for more information.
3.3.1
INCREASING PRESSURE
n
Place outlet selection valve (6) to VENT position.
o
Close test outlet valve (4).
For small pressure changes, it may be possible to reach the desired pressure using the VV
only, proceed to Step
s
below.
p
Open pressure equalization valve (3) (pull valve outward).
OPENING THIS VALVE MAY RESULT IN A SUDDEN CHANGE IN THE TEST PRESSURE.
Ensure conditions are such that this either does not happen or that its effects
are inconsequential.
q
Place VV piston (2) at appropriate position, see Section 3.1.3.
r
Open test inlet valve (1) until the approximate desired pressure is reached. Care should
be taken not to overrange the test.
s
Close equalization valve (push valve inward).
t
Adjust VV knob until desired pressure is obtained (or until the piston floats when
connected to a piston gauge).
Maximum differential pressure across the VV piston is 150 psi (1 MPa). Pressures above
150 psi (1 MPa) will automatically open the equalization valve
u
To continue increasing pressures, repeat Step
p
or
t
shown above.
Page
7
© 2001 - 2007
DH Instruments, a Fluke Company
