Ashcroft 1327D - Pressure Gauge Comparator - Manual (Page 10)

3.3.6 To Dismantle
To replace the tester in its case, remove the gauge offset
pipe assembly (64 or 66) and the piston and cylinder
assembly (67 or 79). Install shipping plugs in body outlet
holes. Screw in the displacement valve (41) until it stops.
Close the vent plug (35). Open the release valve (37)
approximately _ turn. Replace the tester in its case, reser-
voir last. Engage the spring clip catch.
3.3.7 General Precautions
It is important that the deadweight tester be connected to
a leak tight system.
The deadweight tester should be set-up so that the axis of
the located piston is vertical, the weights carefully cen-
tered on that axis, and the piston rotated during use. The
purpose of the rotation is to spread the lubricant over the
entire surface between piston and cylinder, so that there
will be no metal-to-metal contact. If rotation is not main-
tained, the lubricant film will not cover the surface properly,
and readings will be in error.
The high and low pressure piston assemblies have an
internal overload stop, which prevents the piston and cylin-
der from being forced apart if weights are accidentally
removed.
3.3.8 Operating Fluids
Standard Tester:
Any medium weight oil may be used (including automotive
oils S.A.E. 10, 20 or 30) S.A.E. 20-W recommended.
Hydraulic Tester:
Any hydraulic fluid (silicate or phosphate base). Skydrol or
Pydraul is suitable.
For normal operation, it is not necessary to change the
weight of oil for various pressures. A lighter oil may be
used where low pressures are being checked, and a heav-
ier oil where higher pressures are being tested.
The reservoir can be refilled while the tester is operating
under pressure.
3.3.9 Caution
Standard testers designed for oil service may not be used
with water for oxygen service.
3.3.10
Hydraulic service testers should not be filled with water or
any oil other than hydraulic fluid. Serious pump failure may
occur due to O-ring damage.
3.4. Installation Type 1327
3.4.1 Set up Procedure (See Figures 2-2)
To remove the test pump from the case, release the spring
clip, depressing the clip by hand, grasp the pump reser-
voir, and lift up the back end of the pump assembly.
Remove the two plastic shipping plugs from the outlet con-
nections. Remove the threaded filler plug (35) from reser-
voir filling hole. Remove the offset pipe (64) or (66) from
the carrying case and connect to the inner pump body out-
let as shown in Figure 2-2. Remove the straight pipe
extension (58), and assemble to outer vertical pump body
outlet as shown in Figure 2-2.
3.4.2 Connecting The Gauge (See Figure 2-2)
Select a test gauge that is adequate for the pressure
range desired. Assemble the test gauge to the straight
pipe extension, using adapter nut (62), collar (61), adapter
(60) and reducer bushing (59).
Seal the connection by tightening nut adapter (62) and
adapter (60) until the coned end of the pipe is forced into
the gauge socket. Rotate the gauge for viewing by loosen-
ing nut adapter (62), setting the gauge to the desired posi-
tion, and re-tightening nut adapter.
Repeat the above procedure to connect the gauge being
tested to the offset pipe assembly (64) or (66).
3.4.3 Bench Space Required
Allow a space:
10 inch (2.5 cm) width
23 inch (5.8 cm) depth
22 inch (5.6 cm) height allows for testing gauges up to 8.5
inch (250 mm) size
3.4.4 Storage Space Required
10
1 ⁄
2
inch (27 cm) width
22 1 ⁄
2
in (57 cm) depth
10 inch (25 cm) height
Storage space dimensions are larger than actual size of
test pump carrying case by approximately 0.5 inch (1.3
cm), in order to facilitate ease of handling in storage.
3.5 Operation 1327D
3.5.1 Test Gauge Selection
The portable test pump is used for calibrating instruments
such as pressure gauges, pressure switches or other
pressure devices rated up to 10,000 psi (70,000kPa).
First, select the proper test gauge, depending upon the
pressure range desired. When priming the pump a test
gauge rated to 10,000 psi (70,000kPa) should be used.
3.5.2 Priming The Pump
The offset pipe (64 or 66 Figure 2-2) and straight pipe
extension (58) should already be secured in place and the
reservoir should contain the operating fluid (refer to instal-
lation Section 3.4).
Close the release valve (37) by turning it clockwise and
open the air vent by loosening the filler plug (35) a few
turns. The shuttle valve (30) should be pulled outward
from the pump body, the end of the knob approximately
even with the edge of the drip pan. In this position the high
volume displacement mode is selected and the pump is
self-priming. Operate the pump handle several times using
full strokes, until you see fluid appear at the top of the
straight pipe extension. Connect the test gauge to it (refer
to Installation Section 3.4 for proper gauge connection).
Operate the pump handle a few more times until fluid is
observed at the end of the offset pipe. Connect the gauge
or other device to be tested to the offset pipe. For purpos-
es of priming, the device must be designed to withstand
the full operating pressure of 10,000 psi (70,000kPa). If a
lower range device must be used, extreme care must be
exercised to avoid overpressuring its pressure element.
Seal the connection to the device by tightening nut adapter
(62) and adapter (60) until the coned end of the pipe is
forced into its inlet. If necessary, rotate the device for view-
ing by loosening nut adapter (62), set it to the proper posi-
tion and retighten nut adapter.
Again, operate the pump handle a few more times. After a
few strokes positive pressure will develop and the pump
handle will begin to resist pumping action. Raise the pump
handle to its uppermost travel position. Loosen the bleed
screw (51) a half turn counter clockwise and slowly oper-
ate the pump handle through a downward stroke until fluid
flows steadily from the bleed vent. Close the bleed screw
just prior to completing the downward handle motion.
Repeat this action until no air bubbles are observed in the
fluid flow. (Note – the bleed screw must be closed when
the handle is being raised). Push the shuttle valve in