User Guide

ManualsBrandsBarber Colman ManualsHVAC Replacement Parts5/8" O.D Flare Valve (.4 cv)

Application

VB-7212 series single seat, stem up open, two-way

valves control water from 20 to 281°F (-7 to 138°C) or

steam to 281°F (138°C) maximum in heating or air

conditioning systems. They are used for two-position or

proportional control applications. Valve assemblies

require an actuator and a valve linkage that must be

purchased separately.

Danger:

Do not use for combustible gas applications.

The VB-7212 series valve packings are not rated for

combustible gas applications, and if used in these

applications, gas leaks and explosions could result.

Features

• 5/8" O.D., 45° SAE flared end fittings.

• Equal percentage flow characteristics for two-

position or proportional control of water or steam.

• 250 psig pressure rating per ANSI Standards

(B16.15–1985) for cast bronze bodies.

• Spring-loaded TFE packing.

Applicable Literature

• TAC Valve Products Catalog, F-27384

• TAC Cross-Reference Guide, F-23638

• TAC Reference Manual, F-21683

• TAC Application Manual, F-21335

• Control Valve Sizing, F-13755

• Valve Selection Chart for Steam, F-11366

• Valve Selection Chart for Water, F-11080

• EN-205 Water System Guidelines, F-26080

VB-7212 Series

5/8" O.D., 45° SAE Flared

Stem Up Open, Two-Way Valves

General Instructions

Summary of content (8 pages)

PAGE 1
VB-7212 Series 5/8" O.D., 45 ° SAE Flared Stem Up Open, Two-Way Valves General Instructions Application VB-7212 series single seat, stem up open, two-way valves control water from 20 to 281°F (-7 to 138°C) or steam to 281°F (138°C) maximum in heating or air conditioning systems. They are used for two-position or proportional control applications. Valve assemblies require an actuator and a valve linkage that must be purchased separately. Danger: Do not use for combustible gas applications.
PAGE 2
SPECIFICATIONS Table-1 Specifications/Models. Valve Body Series VB-7212-0-4-P Specifications Service Chilled or Hot Water and Steam Flow Characteristics (Figure-1) Equal Percentage Action Stem Up Open Sizes 5/8" O.D.
PAGE 3
Flow Characteristics All valves have modified equal percentage flow characteristics. That is, for equal increments of valve stem stroke, the change in flow rate with respect to valve stroke may be expressed as a constant percent of the flow rate at the time of the change. The change of flow rate with respect to valve stroke is relatively small when the valve plug is near the valve seat and relatively high when the valve plug is nearly wide open.
PAGE 4
321 psig (2218 kPa) Temperature — °F (°C) 300 (149) 250 (121) 200 (93) Maximum Media Temperature 281°F (138°C) 150 (65) 100 (38) 50 (10) Minimum Fluid Temperature 20°F (-7°C) VB-7212-0-4-P 150 (1034) 50 (345) 100 (689) 250 (1724) 200 (1379) 350 (2458) 300 (2068) 400 (2758) Pressure — psig (kPa) Figure-2 Temperature and Pressure Ratings for VB-7212 Series Valve Bodies.
PAGE 5
Cv Equation Cv = GPM ΔP = ΔP ( GPM 2 ) Cv GPM = C v ΔP Where: Cv = Coefficient of flow GPM = U.S. gallons per minute (60°F, 15.6°C) ΔP = Differential pressure in psi (pressure drop) Steam Two-position Two-position zone valves and direct radiation valves are normally sized using a minimum of 10% of inlet pressure (psig). Proportional Proportional control valves are normally sized using: • For low pressure (15 psig or less), use ΔP of 80% of gauge inlet pressure.
PAGE 6
Cavitation Limitations on Valve Pressure Drop A valve selected with too high a pressure drop can cause erosion of discs and/or wire drawing of the seat. In addition, cavitation can cause noise, damage to the valve trim (and possibly the body), and choke the flow through the valve. Do not exceed the maximum differential pressure (pressure drop) for the valve selected.
PAGE 7
INSTALLATION Inspection Requirements Inspect the package for damage. If damaged, notify the appropriate carrier immediately. If undamaged, open the package and inspect the device for obvious damage. Return damaged products. • Tools (not provided): Pipe wrenches • Training: Installer must be a qualified, experienced technician • Appropriate accessories Caution: • Install the valve with the flow in the direction of the flow arrow (“A” port is the inlet and “AB” port is the outlet).
PAGE 8
Water System Maintenance All heating and cooling systems are susceptible to valve and system problems caused by improper water treatment and system storage procedures. These guidelines are provided to help avoid valve and water system problems resulting from improperly treated water or storage procedures in cooling and hot water systems, and to obtain maximum life from TAC valves. Durability of valve stems and packings is dependent on maintaining non-damaging water conditions.