Buying Guide

NIBCO INC. WORLD HEADQUARTERS • 1516 MIDDLEBURY ST. • ELKHART, IN 46516-4740 • USA • PH: 1.800.234.0227
TECH SERVICES PH: 1.888.446.4226 • FAX: [phone] • INTERNATIONAL OFFICE PH: +1.574.295.3327 • FAX: [phone]
www.nibco.com
86
www.nibco.com
AHEAD OF THE FLOW
®
Scope
Flanging is used extensively for plastic process lines that
require periodic dismantling. Plastic flanges and factory flanged
valves and fittings in PVC, CPVC, PVDF and polypropylene are
available in a full range of sizes and types for joining to pipe
by solvent welding, threading, or thermosealing as in the case
with polypropylene and PVDF. Gasket seals between the
flange faces should be an elastomeric full flat-faced gasket
with a hardness of 50 to 70 durometer A. NIBCO can provide
polychloroprene (CR) gaskets nominal sizes 1/2 through 8 having
a 1/8 inch thickness. For chemical environments too aggressive for
polychloroprene other more resistant elastomers should be used.
Dimensions
Bolt circle and number of bolt holes for the flanges are the
same as Class 150 metal flanges per ASME B16.5. Threads are
tapered iron pipe size threads per ASME B1.20.1. The socket
dimensions conform to ASTM D2467, which describes nominal
sizes 1/2 thru 8. Internal NIBCO specifications have been
established for the size 10 and 12 PVC patterns.
Pressure Rating
As with all other thermoplastic piping components, the
maximum non-shock operating pressure is a function of
temperature. Maximum pressure rating for NIBCO
®
valves,
unions and flanges is 150 psi. Above 100°F refer to the chart.
Maximum Operating Pressure (psi)
N/R Not Recommended
Flanged Joints
Operating Temp. °F PVC
100 150
110 135
120 110
130 75
140 50
150 N/R
160 N/R
170 N/R
180 N/R
190 N/R
200 N/R
250 N/R
280 N/R
ASME B16.5 Dimensional Data for Flanges and Flanged
Fittings
(Dimensions and Bolts Conform to Class 150 Steel Flanges)
Sealing
The faces of the flanges are tapered back away from the orifice
area at a 1/2 to 1º pitch, so that when the bolts are tightened,
the faces will be pulled together generating a force in the
water way area to improve the sealing.
INSTALLATION TIPS
Once a flange is joined to the pipe, the method for joining two
flanges together is as follows:
1. Make sure that all the bolt holes of the mating flanges
match up. It is not necessary to twist the flange and
pipe to achieve this.
2. Insert all bolts.
3. Make sure that the faces of the mating flanges are not
separated by excessive distance prior to bolting down
the flanges.
4. The bolts on the plastic flanges should be tightened by
pulling down the nuts diametrically opposite each other
using a torque wrench. Complete tightening should be
accomplished in stages and the final torque values
shown in the table should be followed for the various
sizes of flanges. Uniform stress across the flange will
eliminate leaky gaskets.
Dimensions
Drilling
Nominal Outside Diameter Diameter of
Size Diameter Number of Bolt Bolt Circle
(inches) of Holes (Inches) (inches)
1/2 3.50 4 1/2 2.38
3/4 3.88 4 1/2 2.75
1 4.25 4 1/2 3.12
1
1
/4 4.62 4 1/2 3.50
1
1
/2 5.00 4 1/2 3.88
2 6.00 4 5/8 4.75
2
1
/2 7.00 4 5/8 5.50
3 7.50 4 5/8 6.00
4 9.00 8 5/8 7.50
6 11.00 8 3/4 9.50
8 13.50 8 3/4 11.75
10 16.00 12 7/8 14.25
12 19.00 12 7/8 17.00
Revised 4/26/2019