Materials
All domestic cold water piping shall be Copper pipe for all piping less than 4”. Piping 4” and greater, and all non-potable water piping, shall be galvanized Steel pipe. The use of polyvinyl chloride, chlorinated polyvinyl chloride, or poly-butylene material shall not be permitted. Connection to dissimilar metals shall be connected with a dielectric union. All water piping shall be fully insulated per Specifications. Drinking water systems and plumbing products shall be lead-free as defined by the Safe Drinking Water Act (SDWA) and certified by an ANSI Accredited third-party certification body.
Sizing
Piping shall be properly sized to maintain proper water velocities within the piping of between 4 and 8 feet per second. The maximum allowable pressure drop in the system shall be 2 PSI per 100 feet of pipe run. All pipe sizing shall meet applicable codes and standards. If considerations are being made for future demand, notes shall be provided on plans and estimates of future demand shall be added to the calculations for the entire system.
Service
Incoming water service shall be a combined domestic and fire protection service. Service shall be extended underground from the point of service connection to the proposed interior Water Room. Water service arrangement and valve installation shall be in accordance with the Department of Water Management Standards.
Service operating pressure shall be a minimum of 30 PSI at the elevation of the highest fixtures within the building, not to exceed 80 PSI. Minimum required pressure at the furthest fixture connection shall be 40 PSI with a 30 PSI suction pressure. A domestic booster pump system shall be used to maintain these pressures if service pressure and flow rate are not sufficient and stable.
Where domestic service size exceeds 2-inch diameter, increase the incoming service one pipe size above the required fire service size. Inside the building, provide a blind flange for continuation to fire service and extend water to domestic service. Size shall be in accordance with the design criteria and the Chicago Plumbing Code. Install dual meter arrangement consisting of shut-off valves, strainers, check valves, and 4-inch size domestic water meters.
Distribution
For the proposed building, extend new domestic water from booster pump assembly (if required) to building supply plumbing including; water heaters, plumbing fixtures, equipment, mechanical fill systems, hydrants, etc., for the proposed building. Distribution throughout the facility shall be through piping systems located above corridor ceiling areas or accessible vertical shafts. Piping installed under slab areas shall not be permitted, unless accessible for maintenance of the system.
Backflow Prevention
Shall be provided at all interconnections between the potable water system and points of possible contamination, in accordance with the requirements of the Chicago Plumbing Code. All hose bibs shall include vacuum breakers. Backflow preventers serving laboratory faucets shall be integrated into the faucet, except for faucets located within fume hoods. All fume hood sinks shall be served through an elevated vacuum breaker installed outside the fume hood at a minimum 7’-6” AFF. Include an inline backflow prevention device in all Janitor’s Closet and maintenance areas where connections to vendor cleaning systems may be used. Provide a testable dual check valve to service any hose bibb connections. Multiple hose bibbs may be attached to a single dual check valve. This piping shall be labeled as non-potable throughout its run.
Wall Hydrants
Shall be provided at 150-foot intervals around the perimeter of the building. Provide non-freeze wall hydrants and/or roof hydrants for any vegetated roof or air cooled mechanical equipment. Locate them within a 75’ maximum hose run. Provide a minimum of one hydrant per each side of the building.
Roof Hydrants
Roof Hydrants shall be provided on roofs near mechanical rooftop equipment if water is required for periodic equipment maintenance. Plumbing EOR shall coordinate the requirement for a Roof Hydrant for each piece of equipment with Mechanical EOR. Each roof hydrant shall be provided with a testable double check valve for backflow prevention or connected to a common non-potable water line. Roof Hydrants shall be frost proof.
Valving
All branch piping from the mains shall include local isolation valves. These valves shall be located in an easily accessible space and may require an access door (lockable) coordinated with other trades. Provide final connections to all items requiring water, including: all piping, fittings, valves, air chambers, di-electric unions, vacuum breakers, hangers and supports, Code required backflow preventers, control valves, and miscellaneous related items. Provide rough-in and final connections to all food service equipment. Water supply (hot and/or cold) to the lavatories, sinks, and drinking fountains shall have angle stops with loose key handles.
Thermal Expansion
The Domestic Cold Water system shall take into account the need for thermal expansion compensation. The use of expansion loops, fittings and thermal expansion tanks may be used to compensate as required.