A5
Parker Hannifin Corporation
Tube Fittings Division
Columbus, Ohio
http://www.parker.com/tfd
4300
Catalog
Seal-Lok™ O-Ring Face Seal Tube Fittings
Dimensions and pressures for reference only, subject to change.
A
Fig. A1 — Captive O-ring Groove (CORG) Cutaway with Parker's
trap seal
Seal-Lok Introduction
The Seal-Lok fitting meets or exceeds the strict requirements
of SAE J1453 and ISO 8434-3. It is an O-ring face seal type
fitting that consists of a nut, a body, an O-ring and a sleeve. As
shown in Fig. A2, the tube is flanged to 90° (or the tube may
be brazed instead to a braze-type sleeve). When the fitting is
assembled, it compresses an O-ring in the precision machined
groove of the fitting body to form a leak tight seal.
Seal-Lok fittings are suitable for a wide range of tube wall
thicknesses and are readily adaptable to inch or metric tubing
and hose. (Please refer to
Tables U3
an
d U4
located in the
Ap-
pendix section
for min./max. tube wall thickness for inch and
metric tubing, respectively). Seal-Lok’s leak-free design and
rugged construction make it suitable for a wide range of applica-
tionswherehigher pressures, vibrationand impulseareprevalent.
How Seal-Lok Fittings Work
The Seal-Lok fitting body face contains a high durometer trap
seal to maximize retention in a precision machined groove also
known as a Captive O-Ring Groove (CORG) referenced in Fig.
A1. As the nut is tightened onto the fitting body, the trap seal is
compressed between the body and flat face of the tube flange
or braze sleeve to form a tight, positive seal (see Fig. A2).
As the two faces come in contact, further tightening of the nut
produces a sharp rise in assembly torque. A solid pull of the
wrench at this point, to recommended assembly torque, com-
pletes the assembly.The sharp torque rise gives a “solid feel” at
assembly, minimizing the possibility of over tightening.
Because the sealing surfaces are flat and perpendicular to the
assembly pull, they remain virtually free of distortion during
assembly, giving Seal-Lok fittings practically unlimited remake-
ability.The O-ring should be inspected at each disassembly and
replaced when necessary.
See the
O-Rings and Seals section
for information on replacement ORFS O-rings.
Because the tubing is a sealing surface, it must be smooth, free
of any nicks, scratches, spiral tool marks, splits or weld beads.
Seamless tube is recommended for Seal-Lok fittings for ease
in flanging and bending. Certain types of harder tubes that are
not fully annealed may not be suitable for flanging due to the
potential for immediate or long-term cracking of the tube flange.
For specific tube type and wall thickness recommendations,
please see
Table U3 i
n the
Appendix Section.
Reference locations
Dynamic Pressure Ratings:
Please refer to the last column
of the part number tables located on the following pages of this
section for the appropriate dynamic pressure ratings.
Recommended Tube Wall Thickness:
Please refer to
Table
U3
located in the
Appendix section.
Assembly and Installation:
Please refer to
Seal-lok Assembly
located within the Assembly/Installation section of this catalog.
Standard material specifications:
Please refer to
Table U1
located in the
Appendix section.
Fig. A2 — Seal-Lok Union cutaway with flanged
and brazed assemblies
Braze Sleeve
O-ring (Trap-Seal)
Parflange
Sleeve
Nut
Fitting Body
Fig. A3 — Seal-Lok Works with Inch or Metric Tube and Hose
Body
Inch Sleeve and Tube
Metric Sleeve and Tube
Nut
Hose