Tennessee LLP Limited Licensed Plumber

Full-open valves are required at locations such as near the curb, at the meter discharge, at the building entrance and at each water heater, while shutoff valves are what is required on the supply to each sillcock, each appliance and each fixture supply (a lavatory fixture supply in a one-family dwelling needs a shutoff valve, not a full-open valve).

Equal spacing makes the center-to-center lengths equal, but because each fitting type has its own fitting allowance, assemblies using different fittings (90° ell vs 45° ell) have different end-to-end cut lengths.

Water service pipe/tubing must have a working pressure rating of not less than 160 psi at 73.4°F (IPC 605.3), while hot water distribution pipe must be rated not less than 100 psi at 180°F (IPC 605.4).

An approved ASSE 1003 pressure-reducing valve with strainer is required where static water pressure in the building exceeds 80 psi (reducing distribution pressure to not greater than 80 psi static), whereas a booster pump's low-pressure cutoff must act when a positive pressure of 10 psi or less occurs on the pump suction side.

Per IPC 424.2 urinals shall not be substituted for more than 67 percent of required water closets in assembly and educational occupancies, versus a 50-percent limit in all other occupancies.

Each tested section of drainage/vent must hold not less than a 10-foot head of water for not less than 15 minutes, while the water supply system (piping other than plastic) may be tested with air at not less than 50 psi held for not less than 15 minutes.

A stack vent is the vent extension of the drainage stack itself (sized from Table 906.1, e.g., 1½ in permitted for a 3 in stack with 21 DFU up to 32 ft developed length), while the vent stack is a separate vertical vent pipe that circulates air through the drainage system, connecting near the base of the soil stack and rejoining the stack vent above the highest fixture.

Where soft, poor load-bearing material is found at the trench bottom, overexcavate not less than two pipe diameters and backfill to grade with fine gravel, crushed stone or concrete; separately, loose earth backfill is placed in 6-inch layers and tamped until the pipe crown is covered by 12 inches of tamped earth before the remaining backfill is placed.

Per IPC 504.6 item 10, the discharge pipe shall terminate not more than 6 inches above the floor or flood level rim of the waste receptor (maximum) and not less than two times the discharge pipe diameter above it (minimum).

One miter cut across the pipe produces a bend of twice the cut angle, so the miter angle is always one-half of the desired fitting angle.

A ¼ bend is 90°, a ⅕ bend is 72°, a ⅛ bend is 45° and a 1/16 bend is 22½°; these match the angles of threaded fittings so the same offset constants apply.

Affected employees must be notified of monitoring results as soon as possible but no later than 5 working days after receipt (in writing or by posting), while the monitoring/exposure assessment records themselves must be kept at least 30 years.