PVC & CPVC Flanges and Flange Fittings
All PVC and CPVC flanges and flange fittings produced by LASCO comply with the perimeters specified in ANSI b16.5. These perimeters include: pressure-temperature ratings, materials, dimensions, tolerances, markings, testing, and methods of designating openings for steel pipe flanges and flange fittings. Ratings are for sizes NPS, 1/2 through NPS 24.
Pressure-temperature Ratings
The pressure-temperature ratings of all LASCO PVC and CPVC flanges are listed as 150 psig at 73° F. Flanges and flange fittings covered by the ANSI b16.5 shall be designated as one of the following:
Class 150, 300, 400, 600, 900, 1500, or 2500.
Except as provided in paragraph 2.5 of ANSI b16.5, these ratings are the maximum allowable non-shock working pressures, expressed as psig at the temperature shown for the applicable material.
The temperature shown for the corresponding pressure rating is the temperature of the pressure-containing shell of the flange or the flange fitting. In general, this temperature is the same as that of the contained fluid. The user is responsible for applications requiring a pressure rating corresponding to a temperature other than that of the contained fluid.
In addition to the foregoing statements, the user should recognize that at elevated temperatures the material may show evidence of creep or gradual relaxation of the flanges, bolts and gaskets may progressively reduce bolt loads. It may be necessary to arrange for periodic tightening of bolts to prevent leakage. Joints subject to substantial temperature extremes of high or low and thermal fluctuations may require the same attention.
In addition to the foregoing conditions, the user should recognize that PVC and CPVC undergo sufficient decrease in impact resistance at low temperatures and cannot safely sustain shock loading, sudden changes of stress or temperature or high stress concentrations.
LASCO's flanges and flange fittings meet all standards set by ANSI. Proper installation and use should ensure high performance and longevity of these products.