Common use of Automatic Control Valves Clause in Contracts

Automatic Control Valves. a. Control valves shall be two-way or three-way pattern as shown, constructed for tight shut off and shall operate satisfactorily against system pressures and differentials. Two-way control valves shall exhibit equal percentage characteristics. Valves with size up to and including 2" shall be screwed with 250 psi ANSI pressure body rating; 2 1/2" and larger valves shall be flanged configuration. Proportional control valves shall be sized for a maximum pressure drop of 4.0 psig at rated flow (except as noted). Two-position control valves shall be line size and shall be provided with a 250 psi static pressure body rating. b. All valves shall be capable of operating in sequence when required by the sequence of operation. All control valves shall be sized by the control manufacturer and shall be guaranteed to meet heating and cooling loads specified. c. All control valves shall be suitable for the pressure conditions and shall close against the differential pressure involved. Valve operator connection type (screwed of flanged) shall conform to pipe schedule in this specification. d. Hot water control valves shall be normally open, single seated type with equal percentage flow characteristics. The valve discs shall be composition type with bronze trim. e. Chilled water control valves shall be single seated type with equal percentage flow characteristics, normally closed. The valve discs shall be composition type with bronze trim. f. Valves shall be sized on the exact pressure drop for the equipment served to prevent over or under sizing the valves. Provide a separate submittal with all of this information included.