
Calibration Solutions
for Pressure
and Flow™
PK-mol-4VCR-1/4SWG
Adaptor Kit
Installation Instructions
ADAPTOR KIT, P/N 401821, INCLUDES
QTY PART NO DESCRIPTION
4 100247 Nut, 1/4 in. SWG
4 100248 Ferrule, front 1/4 in. SWG
4 100249 Ferrule, rear 1/4 in. SWG
1 101984 Port connector, 1/4 in. tube
4 102070 O-ring, 2-202 Brown Viton
1 102145 Adaptor, 4VCR F x 1/4 in. SWG
2 102454 Gland, 4VCR x 1/4 tube
2 102455 Nut, 4VCR F
2 102821 Nut, 4VCR M
1 102916 Adaptor, 4VCR M x 1/4 in. SWG
This adaptor kit is for making flowpath connections
between the 1/4 in. VCR fittings of a molbloc, molstic,
or a metering valve kit, and devices with 1/4 in.
Swagelok type connections. The kit may be used in
combination with other adaptors to connect to
devices with fittings such as NPT or AN-type fittings.
This kit includes enough adaptors to connect to both
the inlet and outlet of one molbloc, or the outlet side
of at least two molblocs, molstics or metering valve
kits.
INSTRUCTIONS
When Using a molstic (without metering valve kit):
A low or mid flow molstic has a 1/4 in. VCR female
outlet fitting. The high flow molstic outlet is normally
1/2 in. VCR, but the molstic comes with an adaptor so
that its outlet can also be 1/4 in. VCR female. Use the
adaptor kit to connect to a molstic in one of the
following ways:
• Connect a device to the molstic using a 1/4 in. tube.
First connect the 4VCR M x 1/4 in. SWG adaptor
to the molstic outlet fitting. The tube will thread
onto the Swagelok end of the adaptor using the
1/4 in. Swagelok nuts and ferrules.
• To reduce the overall length and volume of the
adaptors on a low or mid flow molstic, you may
replace the molstic’s 1/4 in. VCR female union with
either the 4VCR F x 1/4 in. SWG adaptor, or the
4VCR gland with a VCR female nut. These two (2)
adaptors will connect to either a Swagelok tube, or
a Swagelok threaded tip, respectively.
When Adapting from a Metering Valve Kit:
Like the low and mid flow molstics, both the low and
mid/hi flow metering valve kits have a 1/4 in. VCR
female union at their outlet. Follow the instructions for
adapting from the low and mid flow molstic above.
When Connecting to a molbloc (without molstic):
When a molstic is not used, this adaptor kit will
connect a molbloc with 1/4 in. male VCR fittings
directly to devices or tubes with 1/4in. Swagelok
fittings. Depending on what will be connected to the
molbloc, adapt to both the inlet and outlet of the
molbloc in one of the following ways.
• Use both 4VCR glands with both VCR female
nuts.
• Use a combination of one (1) VCR gland with VCR
female nut and the 4VCR F x 1/4 in. SWG adaptor.
• Use the 4VCR gland with VCR male nut to
connect to the molstic’s 1/4 in. VCR female outlet
fitting.
A device with a 1/4 in. Swagelok fitting can be
connected directly to the tube end of the gland
using the 1/4 in. Swagelok nuts and ferrules.

PK-mol-4VCR-1/4SWG Adaptor Kit
Installation Instructions
PROCEDURES FOR MAKING
CONNECTIONS
Soft O-Rings
• Always use the soft Viton O-rings provided for making VCR
connections to the molbloc.
The O-rings supplied for making molbloc and other
VCR
connections are:
• Size: 2-202 (Parker Seal Group, O-Ring Division)
• Material: Fluorocarbon rubber (FKM), Viton
Four (4) O-rings are supplied in this adaptor kit. If
frequent fittings changes will be made, replacement Orings should be purchased. Avoid using a dirty or
damaged O-ring.
To Connect VCR Fittings:
Place the O-ring securely against the sealing
surface inside the female nut.
Insert the male fitting and tighten by hand until
resistance is felt when the O-ring begins to
compress. When connecting an adaptor directly
to the molbloc, hold the molbloc by hand and
rotate the female nut.
Turn the nut an additional 1/2 turn beyond the
point of resistance. A wrench may be used on the
nut if desired, but do not tighten beyond one half
turn. If more than one half turn is needed to make
a leak free connection, the O-ring may be
damaged and should be replaced.
• Never use wrenches to hold the molbloc body.
To make original Swagelok connections,
Seat the tube fully into the Swagelok fitting and,
using fingers, turn the nut until resistance is felt.
Turn the nut 1 1/4 turns beyond this point of
resistance with a wrench.
For reconnecting fittings later, return the nut to the
point of increasing resistance, then turn slightly
more with a wrench.
molbloc and molstic are trademarks, registered and otherwise, of DH Instruments, Inc.
Swagelok and VCR are registered trademarks of the Swagelok Company.
Viton is a registered trademarks of DuPont deNemours Company
Document 560045 020107
DH Instruments, Inc.
4765 East Beautiful Lane
Phoenix AZ 85044-5318
USA
Tel 602.431.9100
Fax 602.431.9559
dhi@dhinstruments.com
www.dhinstruments.com