molbloc, molbloc-S, molbox, molstic and molstic-s are trademarks, registered and otherwise, of
DH Instruments, Inc.
VCR is a registered trademark of the Swagelok Company.
Document 560051a
040715
DH Instruments, Inc.
4765 East Beautiful Lane
Phoenix AZ 85044-5318
USA
Tel 602.431.9100
Fax 602.431.9559
www.dhinstruments.com
Place the flat side of the 60 mm nut plate (Fig 2, 1)
under the molstic-S platform. Align it with the holes in
the platform and the regulator bracket. Hold it in place.
Thread the two M4 socket head cap screws and M4 flat
washers through the regulator bracket and tighten them
securely into the nut plate.
SYSTEM PRESSURIZATION AND
REGULATOR ADJUSTMENT
During system operation, be extremely careful
not to apply pressure in excess of the maximum
operating pressure of the molbox: 600 kPaa
(87 psia) for molbox1-A700K; 250 kPaa (36 psia)
for molbox1-A350K.
Once the test system with molbloc-S and molstic-S has been
completely interconnected, the following procedure should
be used for its safe pressurization and operation.
The outlet pressure of a pressure reducing regulator is
controlled by adjusting the position of the control knob.
Rotating the knob in the clockwise direction raises the outlet
(control) pressure. Counterclockwise rotation, coupled with
venting of the downstream side of the regulator plumbing,
lowers the outlet pressure. molstic-S regulators are NOT
self-venting so the outlet pressure will not decrease with
counterclockwise rotation of the control knob unless the
downstream gas is allowed to escape.
Make final adjustments of control pressure in the direction of
increasing pressure in order to obtain the most accurate and
stable set point.
System Pressurization
Set inlet pressure to minimum:
Turn the regulator’s
adjustment knob counterclockwise until the spring force has
been relieved, and if so equipped close the shut-off
directly downstream of the pressure control regulator.
Open molstic-S flow control/shut off valve(s):
Valves
must be open to allow test gas to fill the test system.
Plug-off/cap-off system:
Place a cap or plug
(as applicable) on the outlet fitting of the test system.
Isolate from vacuum system:
If the outlet plumbing of
the molstic-S flows into a vacuum pump, disconnect or
otherwise isolate from the vacuum system. When capping off
ISO-KF style flanges use overpressure rings to insure a
leak free connection at positive line pressure.
Open DUTs flow control valve:
If the test system
contains a DUT that has flow control capability, it must
be slightly opened in order to allow pressure to pass
through. All that is necessary is a small flow to allow the
system to fully pressurize.
Display system pressure:
Monitor the system pressure as
measured by molbox by pressing the [P&T] function until
the pressure is displayed. Refer to molbox Operation
and Maintenance Manual for details.
Turn on gas supply:
Apply the supply pressure to the
pressure control regulator.
Slowly raise system pressure to desired test pressure:
Rotating the regulator’s control knob clockwise raises
the outlet pressure. Rotate counterclockwise to lower
the outlet pressure. Increase the system pressure to
the desired DUT operating pressure. Make final
adjustments of control pressure in the direction of
increasing pressure in order to obtain the most accurate
and stable set point.
Adjust the regulator to obtain the desired operating pressure.
Provide additional margin only if the final pressure will be within
the safe operating range of the molbox.
Regulator Adjustment
Once the regulator has been adjusted to the desired
pressure its adjusting stem should be locked down to prevent
further adjustments. This will help protect the molbox RPTs
from over-pressurization.
Remove regulator knob cover:
Use a small flat
screwdriver to remove the plastic cap on the top of the
regulator adjustment knob.
Loosen jamb nut:
Using the properly sized socket
wrench, loosen the jamb nut located on top of the
adjustment knob.
Adjust knob position:
Rotate the regulator adjustment
knob clockwise until it gently bottoms out against the
regulator body.
Tighten jamb nut:
Hold the adjustment knob in
position while using the socket wrench to tighten the
jamb nut against the top of the adjustment knob.
Retest system pressure:
Vent the system pressure.
Repeat system pressurization procedure to verify the
regulator pressure setting. Readjust if necessary.
Replace regulator knob cover:
Place the regulator
adjustment knob cover back on top of the knob and
gently snap back in place.
The following parts are included in the shipment:
DESCRIPTION
QTY
PART NO.
Regulator, pressure reducing 1
103230
Regulator bracket
1
123657
Adaptor, 4VCR x 4T
1
102454
Male nut, 4VCR
1
102821
Gasket, 4VCR
4
102183
Quick connect body
1
102459
Quick connect stem
1
102458
Union, 4VCR male
1
103231
SHC screw, #10-32 x 3/8
2
103277-Z
Split lock washer, #10
2
103021-Z
Flat washer, #10
2
103278-Z
SHC screw, M4 x 12
2
101016-Z
Flat washer, M4
2
100918-Z
Nut plate, 60 mm
1
123621