Your HPP-4 positioner will come factory
adjusted for your particular application.
The use of the adjustment procedures
will be necessary upon installation of a
rubber goods replacement kit or any
other disassembly or reassembly of
the positioner.
HPP-4
7
September 1999
SUPPLY
PRESSURE
(psig)
CYLINDER BORE (IN.)
4
5
6
8
10
12
14
VARIABLE ORIFICE NUMBER
Up to 50
3
3
3
4
4
5
6
51-200
2
2
3
3
4
5
5
201-600
2
2
2
3
3
4
5
Important Note: For HPP-4 equipped with VB Series Volume Boosters, set variable orifices between 1 and 2
regardless of the cylinder size. Steady state gas consumption is minimized at 1. For additional information
on VB Series Volume Boosters refer to Accessories section of this manual.
Adjustment Procedure
The sensitivity adjustment drum on one
end of the positioner determines the
sensitivity of the unit.
The variable orifices determine the
stroking speed of the positioner.
Initial Adjustment
1. Adjust the supply regulator:
Adjust the supply regulator to the de-
sired Power Gas pressure. Refer to the
original invoice paperwork supplied
with the product for the appropriate
Power Gas pressure setting. It is im-
perative that adequate supply gas pres-
sure be supplied to the VRP-CH in or-
der to ensure proper operation of the
system and all accessories.
2. Adjust the adjustable orifices:
The adjustable orifices are utilized to
control the volume of gas that is sup-
plied to the HPP-4.
The stroking speed of the system is
proportional to the numerical value of
the adjustable orifice. Adjustable ori-
fice settings are typically equal for both
orifices. However, a few applications
may require unequal settings for each
adjustable orifice. Refer to Fine Tuning
for more information on utilizing une-
qual adjustable orifice settings. Set
both orifices according to the table be-
low.
Notes
:
•
If the HPP-4 is NOT equipped with
VB Series Volume Boosters, set the
variable orifices to the recom-
mended value per the Table below.
If equipped with volume boosters,
see note below the table. To deter-
mine the cylinder bore, look at the
model number stamped on the
stainless steel tag on the top of the
cylinder. The cylinder bore will be
the first number following the first
capital letter “H”. This one or two
digit number following the first “H”
will be the diameter in inches and
will be followed by another letter
(For example, a unit with the model
number 6H8F6FG-H4 has an 8"
bore). If equipped with a PS sensor
HPP-4 Positioner
Adjustment Procedures
