User Guide

ManualsBrandsBarber Colman ManualsHVAC Replacement Parts3/4" Union 2-Way Straight Valve (7.5 cv)

Application

VB-7221 series single seat, stem up closed, 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-7221 series valve packings are not rated for

combustible gas applications, and if used in these

applications, gas leaks and explosions could result.

Features

• Valve sizes 1/2" to 1-1/4"

• 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

• Union end American Standard Taper Pipe Thread

(NPT) connections

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-7221 Series

1/2" to 1-1/4" Union End (Straightway) NPT

Stem Up Closed (Normally Closed)

Two-Way Valves

General Instructions

Summary of content (12 pages)

PAGE 1
VB-7221 Series 1/2" to 1-1/4" Union End (Straightway) NPT Stem Up Closed (Normally Closed) Two-Way Valves General Instructions Application VB-7221 series single seat, stem up closed, 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.
PAGE 2
SPECIFICATIONS Table-1 Specifications/Models.
PAGE 3
Normal Position of Valve Assembly For a valve assembly (valve, linkage, and actuator) to have a normal (spring return) position, the actuator must be of the spring return type. See Table-2 for the normal position of the valve assemblies. Table-2 Required Compatible Actuators/Linkages.
PAGE 4
Rangeability Rangeability is the ratio of rated flow to the minimum controllable flow through a valve. Table-3 lists the rangeability for VB-7221 series valves. Table-3 Rangeability.
PAGE 5
Table-4 Conventional Heating System. a Design Temperature Load Drop °F (°C) Recommended Pressure Dropa (% of Available Pressure) Multiplier on Load Drop 60 (33) or More 50% 1 x Load Drop 40 (22) 66% 2 x Load Drop 20 (11) 75% 3 x Load Drop Recommended minimum pressure drop = 5 psi (34 kPa). Secondary Circuits with Small Booster Pumps: 50% of available pressure difference (equal to the drop through load, or 50% of booster pump head).
PAGE 6
Table-6 Steam Capacity in Pounds Per Hour for VB-7221 Series. Differential Pressure ( ΔP in psi)a Valve Body Part Number Cv Ratin g 0.2 1.6 0.5 4 1 8 1.5 12 2 14 2.5 16 3 18 3.5 20 VB-7221-0-4-1 0.4 2.2 5.9 3.7 9.5 5.8 14 7.8 18 9.7 20 12 23 13 26 15 29 VB-7221-0-4-2 1.3 7.1 19 12 31 19 45 25 57 32 66 38 76 44 86 50 95 VB-7221-0-4-3 2.2 12 32 20 52 32 76 43 96 53 112 64 129 74 145 84 161 VB-7221-0-4-4 4.
PAGE 7
Table-7 Vapor Pressure of Water Table. Additional Valve Sizing Information Water Temp. (°F) Vapor Pressure (psia) Water Temp. (°F) Vapor Pressure (psia) Water Temp. (°F) Vapor Pressure (psia) Water Temp. (°F) 40 50 Vapor Pressure (psia) 0.12 90 0.70 140 2.89 190 9.34 0.18 100 0.95 150 3.72 200 11.53 60 0.26 110 1.28 160 4.74 210 14.12 70 0.36 120 1.69 170 5.99 220 17.19 80 0.51 130 2.22 180 7.51 230 20.
PAGE 8
Table-8 Normal Thread Engagement Between Male Pipe Thread and Valve Body. Valve Size Inches (NPT) Normal Engagement 1/2" 1/2" 3/4" 9/16" 1" 11/16" 1-1/4" 11/16" Right Wrong Pipe threads too long. Pipe interferes with seat. Figure-3 Normal Thread Engagement. Valve Assembly Tighten pipe using this pipe wrench Use pipe wrench to prevent valve from turning Figure-4 Installation of Union End Valves. 8 © Copyright 2006 TAC All Rights Reserved.
PAGE 9
CHECKOUT 1. Make sure the valve stem operates smoothly before installing the valve linkage and the actuator. 2. If the stem does not operate smoothly, it may indicate that the valve was twisted or crushed during installation or that the stem was bent by rough handling. These conditions may require that the valve be replaced. 3. After the piping is under pressure, check the valve body and the connections for leaks. 4. After the valve linkage and the actuator are installed, check their operation. a.
PAGE 10
DIMENSIONAL DATA Table-10 Dimensions for VB-7221 Series Valves (Figure-5). Dimensions in Inches (mm) Valve Body Part Number Valve Size A VB-7221-0-4-1 VB-7221-0-4-2 VB-7221-0-4-3 VB-7221-0-4-4 1/2" 4-3/16 (106) VB-7221-0-4-5 VB-7221-0-4-6 3/4" 4-15/16 (125) VB-7221-0-4-7 VB-7221-0-4-8 1" 6 (152) VB-7221-0-4-9 1-1/4" 6-1/4 (159) a B C 1-1/4 (32) 1-11/16 (43) 1-3/4 (45) D (Stem Up) Ea (Stroke) 1-1/8 (29) 7/16 (11) 1-3/4 (45) 2 (51) Stroke for rated flow. Add up to 1/16 in. (1.
PAGE 12
Copyright 2008, TAC All brand names, trademarks and registered trademarks are the property of their respective owners. Information contained within this document is subject to change without notice. F-24384-2 TAC 1354 Clifford Avenue P.O. Box 2940 Loves Park, IL 61132-2940 www.tac.