VAV Hot Water Coil Piping Package Guide Specifications

Hot Water Coil Piping Packages

The VAV air terminal manufacturer shall provide a complete piping package for each terminal hot water coil.   Piping package shall include supply and return isolation ball valves, automatic flow control valve, electric temperature control valve, and strainer with blow-down valve.   The blow-down valve shall include a hose connection with brass cap and gasket.  Provide unions on the coil header connections.  The bottom supply union shall include a PT Port, and the top return union shall include both a PT Port and Manual Air Vent.  PT ports shall not be required on the control valve where automatic flow control is employed.

The piping package shall consist of a supply and return pair, and be factory assembled and pressure tested to 80 psig.  The package shall ship separate from the air terminal to preclude coil damage, and shall be field installed to the air terminal coil and the building hydronic system. The installing party shall provide any miscellaneous fittings, adapters, etc. to complete the installation and shall have final responsibility for a leak-free system installed per specifications.  Each piping package shall ship with labeling including VAV box tag and location, automatic flow control GPM, control valve CV, and installation instructions.  Direction of flow will be clearly indicated on the piping package.

Where indicated on the drawings, 12” braided stainless steel, reinforced EPDM hoses shall be installed between the coil unions control components on both the supply and return.  Hoses shall be rated for 400 psig operating pressure at 225˚F, and burst pressure greater than 1600 psig.  Swivel connectors shall be supplied at each end of the supply and return pair to connect to unions on the coil header.

A pressure independent automatic flow control valve shall be factory set to the design flow rate, and shall automatically control the flow to within ± 10% of the rated value over an operating range of 2 to 80 psig differential pressure drop across the controller. The valve shall include an internal flow control device/cartridge specific to the design GPM for the air terminal and is removable/replaceable without disconnecting components.  Flow control cartridges using spring technology are not acceptable.  The radiated sound from the automatic flow control shall not exceed 16 dB in the 2ND through 8TH octave bands.  The flow control device/cartridge shall include a lifetime warranty.

Ball valves and Automatic flow control valves shall be made of hot forged brass (UNS C37700) per ASTM B-283 and shall have blow-out proof stems, and shall be rated for 600 psig WOG.  Working pressure rating shall be per ASME B31.9 Building Services Piping.  Threaded fittings ½” through 1½” shall be suitable for 600 psig working pressure rating. 

Strainer and blow-down valve shall be a Y configuration and manufactured from bronze with a brass cap.  Cap shall be sealed with non-asbestos gasket or O-ring. Strainer bodies shall be suitable for 6000 psig WOG at a minimum temperature of 32˚F to 225˚F.  Working pressure rating shall be Class 125.  Strainer screen shall be stainless steel #20 mesh and accessible for cleaning.

Temperature Control Valve & Actuator

(Option 1) 2-Way, 2-Position (Open/Close), Factory Provided
The electric temperature control valve shall be supplied and installed by the VAV air terminal manufacturer in the piping package at the factory.  The pressure testing of the piping package shall be performed after the temperature control valve is installed.

The electric temperature control valve and actuator shall be sized as shown on the plans and be 24vac, 2-way type,  Valve shall be rated for 400 psi with a close off pressure of 60 psi max.  

The actuator control signal shall be compatible with the VAV air terminal controller and shall be 24vac, 2 position open/close, (fail in place)(spring return – N.O.)(spring return – N.C.).

(Option 2) 2-Way Modulating, Factory Provided
The electric temperature control valve shall be supplied and installed by the VAV air terminal manufacturer in the piping package at the factory.  The pressure testing of the piping package shall be performed after the temperature control valve is installed.

The electric temperature control valve and actuator shall be sized as shown on the plans and be 24vac, 2-way type.  Valve shall be rated for 400 psi with a close off pressure of 60 psi max.  

The actuator control signal shall be compatible with the VAV air terminal controller and shall be (floating point control)(0-10vDC proportional control),  (fail in place)(spring return – N.O.)(spring return – N.C.).

(Option 3) Temperature Control Valve by ATC, Factory Installed

The electric temperature control valve shall be supplied by the automatic temperature controls contractor under the Controls Division ___________ and installed by the VAV air terminal manufacturer in the piping package at the factory.  The pressure testing of the piping package shall be performed after the temperature control valve is installed.

(Option 4) Temperature Control Valve by ATC, Field Installed

The electric temperature control valve shall be supplied by the automatic temperature controls contractor under the Controls Division ___________ and installed in the field by the temperature control contract.  Valve connection sizes and type shall be coordinated between parties for use in fabrication of piping packages.