Opening of Quotes - North WTP Raw Water Header Improvements Proj No. 119-011A - Bowen Engineering Corp.

Home Browse Search

Version 2/14/2020 Page - 7 Public Works Quote (iv) Remove all cuttings and foreign matter from the inside of pipe and tubing before installation. Thoroughly clean all pipe, fittings, valves, specials, and accessories before installing. (v) Observe safety precautions with the use of joint primers and solvent cements. Allow air to circulate freely through pipelines to permit solvent vapors to escape. Slowly admit water when flushing or filling pipelines to prevent compression of gases within pipes. (vi) Protect threaded joints at the point of grip by inserting a rubber sheet or other material between pipe and vise. Thread pipe in accordance with the pipe manufacturer’s recommendations. Brush threads clean of chips and ribbons. Then starting with the second full thread and continuing over the thread length, wrap Teflon (PTFE) thread tape in the direction of the threads. Overlap each wrap by one half the width of the tape. Screw the fitting or coupling onto the pipe and tighten by hand. Using a strap wrench only, further tighten the connection an additional one to two threads past tightness. t. Testing of Piping (i) Test all piping except as may be exempted in the Schedule. (ii) Conduct all tests in the presence of the Owner. (iii) Remove or protect any pipeline-mounted devices that may be damaged by the test pressure. (iv) Provide all apparatus and services required for testing, including but not limited to, the following: (i) Test pumps, bypass pumps, hoses, calibrated gauges, test containers, valves, and fittings. (ii) Temporary bulkheads, bracing, blocking and thrust restraints. (v) Unless otherwise specified, Owner will provide water required for testing. (vi) Repair observed leaks and any pipeline failing to meet acceptance criteria. Retest after repair. (vii) Test Procedure: (i) Fill pipeline slowly to minimize air entrapment and surge pressures. Fill rate should not exceed one foot per second in the pipe being tested. (ii) Examine exposed joints and valves, and correct visible leakage. (iii) After the wetting period prescribed above, add fluid to pressurize line to the required test pressure. Maintain test pressure for a stabilization period of 10 minutes before beginning test. (iv) After the stabilization period, maintain test pressure for a two-hour period. Add fluid to restore test pressure if pressure drops 5 psi below test pressure at any time during the test period. (v) Pump from a test container to maintain test pressure. Measure the volume of fluid pumped from the container and record on the test report. Record pressure at the test pump at 15-minute intervals for the duration of the test. (viii) Allowable Leakage Rates: Leakage is defined as the quantity of fluid that must be supplied to the pipeline or any section thereof to maintain pressure within 5 psi of the test pressure during a two-hour period. The two-hour test period shall not begin until after the pipe has been filled, exposed to the required wetting period, air has been expelled and pressure has been stabilized. Allowable leakage rates for piping system are listed below: A. No Leakage: Pipe with flanged, welded, fused, screwed, or soldered joints. (ix) Cleaning and Disinfection (i) All dirt, debris, standing water and any other material shall be removed from the pipes, to satisfaction of the Owner. (ii) All water, dirt, or foreign material accumulated in this operation shall be removed from the pipes, to the satisfaction of the Owner. XVII. VALVES A. Prevailing Specifications: None B. Additions: 1. Remove and salvage existing Pratt stainless steel 12” butterfly valve for new location. 2. Modify cradle to accommodate valve weight 3. Installation: a. Install valves plumb and level unless otherwise approved.