| 1 | Define the Service Fluid | Identify the fluid composition, concentration, temperature, pH, abrasiveness, and cleaning chemicals. | Water, seawater, acids, alkalis, brine, wastewater, slurries, and process chemicals. | Chemical compatibility is primarily controlled by the resin and the corrosion barrier. A resin suitable for water may not be suitable for concentrated chemicals or elevated temperatures. | Review the resin compatibility chart for the exact chemical concentration and maximum continuous operating temperature. Consider permeation and liner requirements. |
| 2 | Choose the Resin Type | Compare chemical resistance, temperature capability, toughness, shrinkage, and cost. | Polyester: economical and suitable for many general-purpose water and wastewater services. Vinyl ester: generally offers better resistance to aggressive chemicals, hydrolysis, and higher-temperature service than standard polyester. Epoxy: provides strong adhesion and low shrinkage, and is commonly selected when mechanical performance or demanding chemical service is important. | Resin selection influences corrosion life, interlaminar strength, dimensional stability, and allowable operating temperature. No single resin is best for every service. | Require documented chemical-resistance data, design temperature limits, cure information, and confirmation that the selected resin meets the project specification. |
| 3 | Compare Reinforcement Architecture | Evaluate glass-fiber type, orientation, winding angle, fiber content, and corrosion-barrier construction. | Common reinforcements include E-glass roving, chopped-strand mat, and stitched fabrics. Hoop-oriented fibers improve circumferential strength; helical or axial fibers contribute to longitudinal and combined-load capacity. | Fiber orientation is as important as fiber quantity. A pipe optimized only for internal pressure may require additional axial reinforcement when exposed to thrust, bending, vacuum, seismic movement, or buried-soil loads. | Request laminate construction details, nominal fiber content, winding angles, liner thickness, and test data for axial, circumferential, and interlaminar properties. |
| 4 | Match Pressure and Temperature Ratings | Check internal pressure, external pressure, surge, vacuum, and temperature together rather than separately. | FRP pipes are often specified by pressure class or design pressure, but allowable pressure can decrease as temperature rises. Vacuum resistance depends strongly on stiffness, wall structure, diameter, support, and ovality. | Pressure cycling, water hammer, thermal expansion, and negative pressure can govern the design even when the normal operating pressure is moderate. | Confirm design pressure, test pressure, surge allowance, maximum continuous temperature, short-term temperature limits, and external-pressure or vacuum calculations. |
| 5 | Assess Structural Performance | Review stiffness, buckling resistance, deflection, axial capacity, fatigue, and support spacing. | Key factors include diameter-to-thickness ratio, ring stiffness, laminate modulus, soil support, burial depth, traffic loading, span length, and restraint conditions. | Unlike isotropic metal pipes, FRP properties vary by direction. A pipe can have high hoop strength but insufficient axial or bending capacity if the laminate is not designed for the actual load case. | Request calculations for buried, above-ground, and submerged conditions as applicable. Check allowable deflection, buckling safety factors, support reactions, and joint loads. |
| 6 | Select the Joint System | Compare sealing method, axial restraint, installation tolerance, pressure capability, and maintenance requirements. | Common systems include gasketed bell-and-spigot joints, restrained gasketed joints, flanged connections, and laminated or bonded joints. | Joint performance may control leakage risk and allowable movement. Restrained joints can transfer axial thrust, while flexible gasketed joints may accommodate limited angular deflection when properly installed. | Verify gasket material compatibility, joint pressure rating, allowable angular deflection, insertion depth, thrust-block requirements, and field inspection procedures. |
| 7 | Check Standards, Testing, and Quality Control | Confirm compliance with the required design standard and inspect manufacturing consistency. | Relevant requirements may address dimensions, hydrostatic pressure, stiffness, joint integrity, chemical resistance, workmanship, marking, and long-term design factors. | Product performance depends on resin cure, fiber placement, void content, liner quality, dimensional accuracy, and quality-control testing—not only on nominal material names. | Specify the applicable standard, inspection plan, test frequency, acceptance criteria, traceability records, hydrostatic testing, and documentation for each production lot. |