ASME B16.5 — Pipe Flanges and Flanged Fittings

ASME B1.20.1 / Manufacturer Guidelines

Thread sealant (pipe dope) should be applied to male threads, not female threads. Applying to female threads pushes excess sealant into the system where it can clog strainers, valves, and control devices.

ASME B16.34 / Crestline Valve Specification

The valve's derated pressure rating of 185 PSI at 200°F does not exceed the operating pressure of 150 PSI by the required 50% safety margin. The specification requires valve ratings to exceed operating pressure by at least 50%, which means 150 PSI x 1.5 = 225 PSI minimum rating at the operating temperature. At 185 PSI derated, the valve only provides a 23% margin. A higher-class valve (e.g., Class 300 instead of Class 150) is needed to provide the required safety factor at the system's operating temperature.

ASME B16.34 / mfr rating

Valve pressure class must meet or exceed the system design pressure; a 125 psi valve on a 200 psi system can fail catastrophically.

ASME B31.1 — Power Piping

Steam supply piping must pitch downward in the direction of flow (away from boiler) to prevent condensate from pooling and causing water hammer. The piping here is back-graded, trapping condensate.

ASME B31.1 — Power Piping, para. 136.4 / Table 136.4

This is compliant. ASME B31.1 (Power Piping) does NOT mandate radiographic (RT) or ultrasonic (UT) examination for every welded joint — mandatory 100% NDE is triggered only by the thresholds in para. 136.4 / Table 136.4: butt welds and branch connections operating above 750°F, OR operating between 350°F and 750°F AND above 1025 psig AND with nominal wall thickness over 1-1/8 in. A 300 PSI (psig) steam main saturates at roughly 421°F and is far below the 1025 psig and 750°F triggers, so it does not meet any of the criteria that require RT/UT. For these service conditions B31.1 calls for visual examination of accessible weld surfaces by a qualified inspector — exactly what was performed. With welds made by a currently ASME-qualified welder and accepted by visual examination, the system meets the code-required examination and may be placed in service. (If this run were boiler external piping directly connected to the boiler, ASME Section I would govern and impose stricter rules — but the scenario describes a distribution main.)

ASME B31.1 / ASHRAE Handbook — HVAC Systems

This is a textbook-correct steam trap installation as taught at UA halls. The F&T trap is appropriate for equipment drains (it handles variable condensate loads and passes air). The strainer upstream protects the trap internals from scale and debris. The check valve downstream prevents condensate backflow from the pressurized return header. Installing the trap at the same level as the drain (no lift) ensures gravity drainage into the trap — any lift before the trap creates a water seal that impedes condensate flow.