How to Guide

96
Plastics Technical Manual
Pipe Size
In Inches
For systems where dismantling is required, flanging is a
convenient joining method. It is also an easy way to join plastic
and metallic systems.
FLANGE BOLT TIGHTENING SEQUENCE
Installation
1. Join the flange to
the pipe using the
procedures shown in
the solvent cementing
or threading sections.
2. Use a full faced
elastomeric gasket which is resistant to the chemicals
being conveyed in the piping system. A gasket
1
⁄8 ” thick
with a Durometer, scale “A”, hardness of 55 -80 is
normally satisfactory.
3. Align the flanges and gasket by inserting all of the bolts
through the mating flange bolt holes. Be sure to use
properly sized at washers under all bolt heads and
nuts.
6. Useatorquewrenchto
tighten the bolts to the
torque values shown
below.
7. Useofthreadlubricant
will ensure proper
torque. Confirm that
the thread lubricant is
chemically compatible
with pipe and fittings.
Recommended Torque
No. Bolt
Holes
Bolt
Diameter
Recommended
Torque ft/lbs
Note:Flangesmeetthebolt-patternrequirementsofANSI/ASMEB16.5
1
⁄2 4
1
⁄2 10 - 15
3
⁄4 4
1
⁄2 10 - 15
1 4
1
⁄2 10 - 15
1
1
⁄4 4
1
⁄2 10 - 15
1
1
⁄2 4
1
⁄2 10 - 15
2 4
5
⁄8 20 - 30
2
1
⁄2 4
5
⁄8 20 - 30
3 4
5
⁄8 20 - 30
4 8
5
⁄8 20 - 30
6 8
3
⁄4 33 - 50
8 8
3
⁄4 33 - 50
10 12
7
⁄8 53 - 75
12 12
7
⁄8 53 - 75
INSTALLATION PROCEDURES
4. Sequentially tighten the bolts corresponding to the
patternsshownbelow.Newboltsandnutsshouldbeused
for proper torque.
5. Ensure that the mating surfaces are in direct contact. A
gap between the flange face and mating surface may result
in flange failure. Do not connect to lug type appurtenances
without additional flange support.
Flanges
• Exceeding recommended flange bolt torque may result in
component damage, system failure and property damage.
• Use the proper bolt tightening sequence as marked on the
flange.
• Make sure the system is in proper alignment.
• Flanges may not be used to draw piping assemblies
together.
• Flat washers must be used under every nut and bolt head.
• Ensure that the mating surfaces are in direct contact. A gap
between the flange face and mating surface may result in
flange failure.
System Operating Temp. 70 80 90 100 110 120 130 140 150 160 170 180 200
Temperature °F (C) (23) (27) (32) (38) (43) (49) (54) (60) (66) (71) (77) (82) (93)
   PVC 150 132 113 93 75 60 45 33 NR NR NR NR NR
   CPVC 150 144 137 123 111 98 87 75 68 60 NR NR NR
Pressure Rating of PVC and CPVC Flanges at Elevated Temperatures
1
⁄2 ” - 6 ”
Pressure
Rating (psi)
NR=NotRecommended