User Bulletin 2

PPFA PUBLICATIONS
PPFA Bulletin Number 2-80

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HYDROSTATIC STRENGTHS AND SUGGESTED PRESSURE RATING FOR CPVC 4120 AT VARIOUS TEMPERATURES

The following language is adapted from Statement J of the Pipe Institute adopted on April 20, 1976.

The ranges in the measured long-term hydrostatic strengths of CPVC 4120 are as follows

Temperature Degrees ^oF Long-Term Hydrostatic Strengths psi

73 4250-4900

140 2050-2250

180 1200-1600

210 740

These were obtained with pipe meeting the requirements of ASTM D2846, D1785* and D2241*. The measured strengths vary depending on the lot of material and the quality of the extrusion. The hydrostatic design basis (categorized long term strength) according to ASTM D2837 is 4000 psi at 73 Degrees P and 1250 at 180 degrees F.

A plot of the long-term strength values versus temperature on semi-log graph paper is attached. Based on this plot the estimated long-term hydrostatic strengths, the hydrostatic design bases and hydrostatic design stresses are as follows:

Temperature
Degrees ^oF Long-Term Hydrostatic Strengths psi Hydrostatic Design Basis Per D2837 psi Design Stress (b) Pressure Rating Basis psi

73 4250 4000 2000

80 4000 4000 2000

90 3500 3150 1600

100 3250 3150 1600

120 2600 2500 1250

140 2050^a 2000 1000

160 1550 1600 800

186 1200^a 1250 500

190 1000 1000 400

200 880 800 ---

210 740 ^a --- ---

a. = Measured.

b. Based on a 0.5 design factor.

The following de-rating factors and pressure ratings were obtained using a 0.5 design factor.

Temperature Degrees^oF	De-Rating Factor	Pressure Rating for SDR 11 CPVC 4120 Pipe psi
73	1.00	400
80	1.00	400
90	0.91	360
100	0.82	325
120	0.65	260
140	0.50	200
160	0.40	160
180	0.25	100
200	0.20	80

*These ASTM Standards no longer contain CPVC piping materials. These products are now covered by ASTM Standards F441 and F442. NOTE: This PPFA User Bulletin is designed to provide guidance in achieving the efficient effective and informed use of plastic pipe. The suggestions and advice contained in this Bulletin are offered merely to provide Plastic pipe users with general frame of reference. Because specific situations may, and often do require special treatment, the suggestions and advice are obviously not universally applicable. Therefore, the user should carefully assess the requirements of his specific situation before making practuniversally applicable. Therefore, the user should carefully assess the requirements of his specific situation before making practical application of anything contained in this publication.

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