Crestline Plumbing Specification (gear operators required on 6 in. and larger)

Crestline Mechanical Specifications / Site Plan

This installation is correct. Per the Crestline plans, all underground piping not directly outside the central plant is rated for 140 degrees F. The 180 degrees F rating is only required for piping immediately outside the central plant where water temperatures are highest. Building-to-building distribution piping at 140 degrees F rating is appropriate because water temperature drops through the distribution network. The 36" cover also meets the minimum burial depth requirement specified on the detail sheet.

Crestline Piping Specification / ASTM B88

Type M copper is NOT acceptable for pressure water piping per the project specification. Type M has the thinnest wall of the three copper tube types (K, L, M) and does not provide adequate long-term reliability for commercial pressure water service. Type L is the minimum required for above-ground pressure water piping, and Type K is required for underground or high-pressure applications. While Type M may be allowed by some residential codes, commercial specifications almost universally prohibit it for pressure service due to its susceptibility to erosion corrosion and pinhole leaks over time.

Crestline Piping Specification / Victaulic Installation Guide

EPDM gaskets are the correct choice for this application. The service temperature of 200°F falls well within the EPDM rating of -30°F to +250°F. EPDM is the standard gasket material for HVAC hydronic systems because of its excellent temperature range, water resistance, and long service life. For systems operating above 250°F (such as high-pressure steam), silicone or other high-temperature gasket materials would be required. The 60 PSI operating pressure is well within grooved coupling pressure ratings.

Crestline Plumbing Specification / ASME B16.34

Valves must be rated to exceed the maximum operating pressure by at least 50% per Crestline specifications. A 100 psi rated valve on a 125 psi system is under-rated and risks catastrophic valve body failure. A minimum 200 psi rated valve (Class 150) is required.

Crestline Seismic Specification

This is correct. Per Crestline spec, in-line duct equipment weighing 75 pounds or less is considered seismically braced by the duct system itself, provided it is rigidly attached to the duct. At 65 pounds, the humidifier is under the 75-pound threshold. The duct's own seismic bracing (transverse at 30 ft max, longitudinal at 60 ft max) provides adequate restraint for the lightweight equipment. If the humidifier exceeded 75 pounds, it would require independent seismic supports regardless of its duct connection.

Crestline Valve Specification

The system operating pressure of 130 PSI exceeds the valve's 125 PSI maximum working pressure rating. Even though the difference is only 5 PSI, operating a valve above its rated pressure violates the specification and creates a safety hazard. The valve body, bonnet gasket, and packing are designed for the rated pressure with appropriate safety margins. At 130 PSI, those safety margins are compromised. The plumber needs to either: (1) select higher-rated valves (e.g., 150 or 200 PSI class), (2) verify with the engineer that 125 PSI valves are acceptable with a pressure-reducing station upstream, or (3) use ball valves rated at 600 PSI for sizes 2 inches and under.