In the event of a conflict among the above listed standards or between the standards and other instructions listed in the specifications and drawing, it should be the Suppliers responsibility to notify the Buyer in writing for a resolution of the conflict prior to starting work.
Temperature, pressure, and fluid service conditions will be supplied by Buyer.
Pipe Installer - The pipe should only be installed by qualified contractors approved by the pipe Manufacturer.
The following data should be submitted to Buyer for approval:
- Product information including pipe specifications, MSDS sheets, installation instructions, and detailed joining procedures.
- Verification that the pipe is suitable for the service.
- Pipe inspection and testing procedures.
- Pipe transportation and storage information and details.
Thermoplastic, Reinforced Thermosetting Plastic (RTRP) and plastic lined pipe should conform to the referenced standards.
Plastic piping should not be used in aboveground flammable materials, combustible liquid or critical water services (Plastic pipe cannot be used above ground in hydrocarbon or other critical services because, in the event of a fire, the pipe will burn; the pipe may also have inadequate resistance to mechanical damage).
Proposals to use plastic pipe in hazardous chemical service should be submitted for approval by Buyer.
To determine the external design pressure for plastic pipe installed underground, underwater, or in other situations which cause external pressure, a safety factor of four must be applied to the critical buckling pressure considering all imposed loads. Plastic-lined piping should have flanged joints. Joint design should be per the following:
- Nonflammable or non-combustible service - The liner should be molded or shaped (lapped over the flange faces) to provide the gasket for the joint.
- Flammable materials, combustible liquid or hazardous liquid service - The flanged joint should be designed to prevent leakage under exposure to heat sufficient to destroy or melt the lining material. Vented piping should not be used.
Maximum allowable deflection of thermoplastic and RTRP pipe, at maximum operating pressure, should be defined by pipe manufacturer, taking into account applicable live and dead loads. Pipe lengths should not exceed 20 ft (6 m) for plastic linings, in order to limit differential thermal expansion between the pipe and the lining. For plastic pipe, the flexibility of the filament winding process allows pipe to be produced in any length from 10 to 40 ft as required.
Temperature limits for plastic and plastic-lined pipe should be as follows: