T.A.C. VB-7223 User Guide

Page 1

TAC

1354 Clifford Avenue P. O. Box 2940 Loves Park, IL 61132-2940 www.tac.com

Application

VB-7223 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. A large selection of factory assembled combinations is available. Consult the TAC Valve Products Catalog, F-27384.

VB-7223 Series

1/2" to 2" Screwed NPT

Stem Up Closed (Normally Closed)

Two-Way Valves

General Instructions

Danger:

The VB-7223 series valve packings are not rated for combustible gas applications, and if used in these applications, gas leaks and explosions could result.

Do not use for combustible gas applications.

Features

• Valve sizes 1/2" to 2"

• 250 psig pressure rating per ANSI Standards

(B16.15–1985) for screwed cast bronze bodies

• Spring-loaded TFE packing

• 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

Page 2

SPECIFICATIONS

Table-1 Specifications/Models.

Specifications

Valve Body Series

VB-7223-0-4-P

Service Chilled or Hot Water and Steam

Flow Characteristics (Figure-1) Equal Percentage

Action Stem Up Closed

Sizes 1/2" to 2"

Type of End Fitting NPT

Body Bronze

Seat Bronze

Valve

Materials

Stem Stainless Steel

Plug Brass

Packing Spring-loaded TFE

Disc EPDM

ANSI Pressure Class (Figure-2) 250 (up to 400 psig below 150°F)

Maximum Inlet Pressure, Steam 35 psig (241 kPa)

Allowable Control Media Temperature 20 to 281°F (-7 to 138°C)

Allowable Differential Pressure for Water

35 psi (241 kPa) Max. for Normal Life (refer to “Cavitation Limitations on Valve Pressure Drop” on page 7)

Allowable Differential Pressure for Steam

Valve Size C

Rating kvs Rating

20 psi (138 kPa)

Complete Valve Body Part Number

0.4 0.3 VB-7223-0-4-1

1/2"

1.3 1.1 VB-7223-0-4-2

2.2 1.9 VB-7223-0-4-3

4.4 3.8 VB-7223-0-4-4

3/4"

5.5 4.8 VB-7223-0-4-5

7.5 6.5 VB-7223-0-4-6

10 8.7 VB-7223-0-4-7

14 12 VB-7223-0-4-8

1-1/4" 20 17 VB-7223-0-4-9

1-1/2" 28 24 VB-7223-0-4-10

2" 40 35 VB-7223-0-4-11

Do not apply above pressure rating to piping system.

Maximum recommended differential pressure in open position. Do not exceed recommended differential pressure (pressure drop) or integrity of parts may be affected. Exceeding maximum recommended differential pressure voids product warranty.

kvs = m3/h (ΔP = 100 kPa) Cv = kvs x 1.156

Close-off Pressure Rating

The close-off pressure rating is dependent on the size of the valve, valve linkage, and actuator. Consult the TAC Valve Products Catalog, F-27384, for close-off ratings.

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 spring return position of valve assemblies.

Table-2 Required Compatible Actuators/Linkages.

Actuator Series Required Valve Linkage Normal Position

MA-5210, MA-5211, MA-5213

MF-5413, MF-5513

AV-7600

MK-2690 AV-7400

MK-4601, MK-4611, MK-4621 AV-401

MK-6601, MK-6611, MK-6621 AV-430

MP-5210, MP-5211, MP-5213 AV-7600

MP-5410, MP-5411, MP-5413

MP-5511, MP-5513

MPR-5610, MPR-5611, MPR-5613

AV-7600 & AV-601

MPR-5713

High ambient temperatures with high media temperatures in the valve may require the use of AV-601 in addition to AV-7600. See General Instructions for AV-7600 (F-26235) and AV-601 (F-19069) for details.

Stem Up

Normally Closed

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. See Figure-1 for typical modified equal percentage flow characteristics of VB-7223 series valve bodies.

100%

90%

80%

70%

60%

50%

Flow

40%

30%

20%

10%

20%

30%

40%

50%

60%

70%

80%

90%

Closed

Stroke

Open

100%

Figure-1 Typical Modified Equal Percentage Flow Characteristics.

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-7223 series valves.

Table-3 Rangeability.

Valve Body

Part Number

VB-7223-0-4-1 5:1 VB-7223-0-4-7 60:1

VB-7223-0-4-2 15:1 VB-7223-0-4-8 75:1

VB-7223-0-4-3 25:1 VB-7223-0-4-9 75:1

VB-7223-0-4-4 40:1 VB-7223-0-4-10 75:1

VB-7223-0-4-5 50:1 VB-7223-0-4-11 75:1

VB-7223-0-4-6 60:1

Nominal

Rangeability

Valve Body

Part Number

Nominal

Rangeability

Temperature/Pressure Ratings

See Figure-2 for temperature and pressure ratings. Consult the appropriate valve linkage general instruction sheet for the effect of valve body ambient temperatures on specific actuators. Ratings conform with published values and disclaimer.

VB-7223-0-4-P (Screwed Cast Bronze Body)

Standards:

321 psig at 281°F

Materials:

Pressure to ANSI B16.15 Class 250 with 400 psig up to 150°F decreasing to

Bronze, ASTM B584

321 psig

(2218 kPa)

300 (149)

250 (121)

200 (93)

150 (65)

100 (38)

Temperature — °F (°C)

50 (10)

Maximum Media

Temperature

281°F (138°C)

Minimum Fluid

Temperature

20°F (-7°C)

(345)

150

(1034)

100

(689)

Pressure — psig (kPa)

VB-7223-0-4-P

(1724)

200

(1379)

Figure-2 Temperature and Pressure Ratings

for VB-7223 Series Valve Bodies.

250

300

(2068)

350

(2458)

400

(2758)

Page 5

VALVE SIZING AND SELECTION

Water Two-position

Two-position control valves are normally selected “line size” to keep pressure drop at a minimum. If it is desirable to reduce the valve below line size, then 10% of “available pressure” (that is, the pump pressure differential available between supply and return mains with design flow at the valve location) is normally used to select the valve.

Proportional

Proportional control valves are usually selected to take a pressure drop equal to at least 50% of the “available pressure.” As “available pressure” is often difficult to calculate, the normal procedure is to select the valve using a pressure drop at least equal to the drop in the coil or other load being controlled (except where small booster pumps are used) with a minimum recommended pressure drop of 5 psi (34 kPa). When the design temperature drop is less than 60°F (33°C) for conventional heating systems, higher pressure drops across the valve are needed for good results (Table-4).

Table-4 Conventional Heating System.

Design Temperature

Load Drop °F (°C)

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).

Recommended Pressure Drop

(% of Available Pressure)

Multiplier on

Load Drop

Secondary Circuits with Small Booster Pumps: 50% of available pressure difference

(equal to the drop through load, or 50% of booster pump head).

Water Capacity

See Table-5 for water capacity of VB-7223 series valves.

Table-5 Water Capacity in Gallons Per Minute for VB-7223 Series.

Valve Body

Part Number

VB-7223-0-4-1 0.4 0.40 0.57 0.69 0.80 0.89 0.98 1.06 1.13 1.20 1.26 1.55 1.79 2.37

VB-7223-0-4-2 1.3 1.30 1.84 2.3 2.6 2.9 3.2 3.4 3.7 3.9 4.1 5.0 5.8 7.7

VB-7223-0-4-3 2.2 2.2 3.1 3.8 4.4 4.9 5.4 5.8 6.2 6.6 7.0 8.5 9.8 13

VB-7223-0-4-4 4.4 4.4 6.2 7.6 8.8 9.8 11 12 12 13 14 17 20 26

VB-7223-0-4-5 5.5 5.5 7.8 9.5 11 12 13 15 16 17 17 21 25 33

VB-7223-0-4-6 7.5 7.5 11 13 15 17 18 20 21 23 24 29 34 44

VB-7223-0-4-7 10 10 14 17 20 22 24 26 28 30 32 39 45 59

VB-7223-0-4-8 14 14 20 24 28 31 34 37 40 42 44 54 63 83

VB-7223-0-4-9 20 20 28 35 40 45 49 53 57 60 63 77 89 118

VB-7223-0-4-10 28 28 40 49 56 63 69 74 79 84 89 108 125 166

VB-7223-0-4-11 40 40 57 69 80 89 98 106 113 120 126 155 179 237

Rating

12345678910152035

Differential Pressure (

ΔP in psi)

Cv Equation

Cv=

GPM

ΔP

ΔP=

GPM

()

GPM = Cv

ΔP

Where:

Cv= Coefficient of flow GPM = U.S. gallons per minute (60°F, 15.6°C) ΔP = Differential pressure in psi (pressure drop)

Page 6

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.

• For steam pressures greater than 15 psig, use ΔP of 42% of absolute (gauge plus 14.7)

inlet pressure.

• When the C

steam valves using a pressure drop greater than 42% of the absolute inlet pressure.

Steam Capacity

See Table-6 for steam capacity of VB-7223 series valves.

Table-6 Steam Capacity in Pounds Per Hour for VB-7223 Series.

Valve Body

Part Number

VB-7223-0-4-1 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-7223-0-4-2 1.3 7.1 19 12 31 19 45 25 57 32 66 38 76 44 86 50 95

VB-7223-0-4-3 2.2 12 32 20 52 32 76 43 96 53 112 64 129 74 145 84 161

VB-7223-0-4-4 4.4 24 65 41 105 64 153 86 192 107 225 127 257 148 289 168 322

VB-7223-0-4-5 5.5 30 81 51 131 80 191 107 240 133 281 159 321 185 362 210 402

VB-7223-0-4-6 7.5 41 111 70 178 110 260 146 328 182 383 217 438 252 493 286 548

VB-7223-0-4-7 10 55 147 93 238 146 347 195 437 243 511 289 584 336 658 381 731

VB-7223-0-4-8 14 76 206 130 333 204 485 273 612 340 715 405 818 470 921 534 1024

VB-7223-0-4-9 20 109 295 186 475 292 694 390 874 485 1021 579 1168 671 1315 763 1462

VB-7223-0-4-10 28 153 413 260 666 409 971 546 1224 679 1430 810 1636 939 1841 1068 2047

VB-7223-0-4-11 40 218 590 372 951 584 1387 780 1749 970 2043 1157 2337 1342 2631 1526 2925

Values are for saturated steam (K = 1). Left column under each inlet pressure is for two-position control, and right column is for proportional control.

Rating

2 psig Inlet 5 psig Inlet 10 psig Inlet 15 psig Inlet 20 psig Inlet 25 psig Inlet 30 psig Inlet 35 psig Inlet

0.2 1.6 0.5 4 1 8 1.5 12 2 14 2.5 16 3 18 3.5 20

required is between two valve sizes, select the larger size. Do not size

Differential Pressure (

ΔP in psi)

Cv Equation

Cv=

ΔP • P2

Where:

Cv= Coefficient of flow Q = Lbs. per hour of steam ΔP = Differential pressure in psi (pressure drop) P2 = Outlet pressure in psia (absolute) (P2 = Inlet pressure + 14.7 – ΔP) K = 1 + (0.0007 x °F superheat) (K = 1 for saturated steam)

ΔP • P23C

Page 7

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.

The following formula can be used on higher temperature water systems, where cavitation could be a problem, to estimate the maximum allowable pressure drop across the valve:

Pm = 0.5 (P1 – Pv)

Where:

Pm = Maximum allowable pressure drop (psi) P

= Absolute inlet pressure (psia)

Pv = Absolute vapor pressure (psia) (refer to Table-6 or Table-7)

Note:

Add 14.7 psi to gauge supply pressure to obtain absolute pressure value.

For example, if a valve is controlling 200°F water at an inlet pressure of 18 psig, the maximum pressure drop allowable would be:

Pm = 0.5 [(18 + 14.7) – 11.53] = 10.6 psi (Vapor pressure of 200°F water is 11.53 psia.)

If the pressure drop for this valve is less than 10.6 psi, cavitation should not be a problem.

Systems where cavitation is shown to be a problem can sometimes be redesigned to provide lower inlet velocities. Valves having harder seat materials should be furnished if inlet velocities cannot be lowered.

Table-7 Vapor Pressure of Water Table.

Additional Valve Sizing Information

Water

Temp.

(°F)

40 0.12 90 0.70 140 2.89 190 9.34

50 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 20.78

Vapor

Pressure

(psia)

Water

Temp.

(°F)

Vapor

Pressure

(psia)

Water

Temp.

(°F)

Vapor

Pressure

(psia)

Water

Temp.

(°F)

For additional valve sizing information, see:

• CA-28 Control Valve Sizing, F-13755

• Valve Selection Chart Water, F-11080

• Valve Selection Chart Steam, F-11366

• Valve Sizing Slide Rule, TOOL-150

Vapor

Pressure

(psia)

Page 8

INSTALLATION

Inspection 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.

Requirements • 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).

• Do not exceed the ratings of the device.

• Avoid locations where excessive moisture, corrosive fumes, or vibration are present.

Mounting 1. The valve should be mounted in a weather-protected area in a location that is within the

ambient limits of the actuator. When selecting a location, allow sufficient room for valve linkage, actuator, and other accessories and for service of the product.

2. The preferred mounting position for the valve is with the valve stem vertical above the valve body. Avoid mounting the valve so that the valve stem is below horizontal.

3. On steam applications where the ambient temperature approaches the limit of the actuator, the valve stem should be mounted 45° from vertical.

4. The valves must be piped with the “A” port as the inlet and the “AB” port as the outlet.

Screwed Valve Bodies

The VB-7223-0-4 series screwed valve bodies conform to American Standard Taper Pipe Threads (NPT).

1. Apply pipe dope sparingly to all but the last two threads of a properly threaded, reamed, and cleaned pipe. Make sure that pipe chips, scale, etc. do not get into the pipe since this material may lodge in the valve seat and prevent proper closing and opening of the valve.

2. Start the joint by hand screwing the pipe into the valve. If the thread engagement feels “right,” turn the pipe by hand as far as it will go.

3. Use a pipe wrench to fully tighten the valve to the pipe. Do not over tighten or strip threads. See Table-8 and Figure-3 for the normal engagement length of the threads. Figure-4 shows a means of tightening the pipe so that the valve is not twisted or crushed.

Table-8 Normal Thread Engagement Between Male Pipe Thread and Valve Body.

Valve Size Inches

(NPT)

1/2" 1/2" 1-1/4" 11/16"

3/4" 9/16" 1-1/2" 11/16"

1" 11/16" 2" 3/4"

Normal Engagement

Valve Size Inches

(NPT)

Normal Engagement

Page 9

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 Screwed End Valves.

Page 10

CHECKOUT

MAINTENANCE & FIELD REPAIR

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. Power the actuator and run the valve to the stem down position. Make sure the

linkage and valve stem move freely. At the stem down position, the valve should be in its full open position.

b. For spring return actuators, allow the actuator to spring return to the stem up

position. Again, the valve stem and linkage should operate smoothly. At the stem up position, the valve should shut off tightly.

Regular maintenance of the total system is recommended to assure sustained performance. See Table-9 for maintenance kit part numbers.

Table-9 Maintenance Kits for VB-7223 Valves.

Water System Maintenance

Valve Body

Part Number

VB-7223-0-4-1

VB-7223-0-4-2 RYB-722-2

VB-7223-0-4-3 RYB-722-3

VB-7223-0-4-4 RYB-722-4

VB-7223-0-4-5 RYB-722-5

VB-7223-0-4-6 RYB-722-6

VB-7223-0-4-7 RYB-722-7

VB-7223-0-4-8 RYB-722-8

VB-7223-0-4-9 RYB-722-9

VB-7223-0-4-10 RYB-722-10

VB-7223-0-4-11 RYB-722-11

Kit includes replacement packing and stem & plug assembly.

Replacement

Packing Assembly

YBA-622-1 TOOL-20-1

Packing Wrench Valve Repair Kit

RYB-722-1

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. Inadequate water treatment or filtration, not in accordance with chemical supplier/ASHRAE handbook recommendations, can result in corrosion, scale, and abrasive particle formation. Scale and particulates can result in stem and packing scratches and can adversely affect packing life and other parts of the hydronic system.

To maintain non-damaging conditions, follow these guidelines:

• Clean the system prior to start up. Use a nitrite or molybdate-based treatment program.

• Use filtration equipment where needed.

• Properly store off-line systems and monitor water treatment results using corrosion test

coupons.

• Follow the advice of a water treatment professional.

• Consult EN-205, Water System Guidelines Engineering Information, F-26080, for

further details.

Page 11

DIMENSIONAL DATA

Table-10 Dimensions for VB-7223 Series Valves (Figure-5).

Part

Number

VB-7223-0-4-1 VB-7223-0-4-2 VB-7223-0-4-3 VB-7223-0-4-4

VB-7223-0-4-5 VB-7223-0-4-6

VB-7223-0-4-7 VB-7223-0-4-8

VB-7223-0-4-9 1-1/4" 2 (51)

VB-7223-0-4-10 1-1/2" 5-3/8 (137) 1-13/16 (46) 2-1/8 (54)

VB-7223-0-4-11 2" 6-1/8 (156) 2-1/16 (53) 2-3/16 (56)

Stroke for rated flow. Add up to 1/16 in. (1.6 mm) for disc seating and compression.

Valve

Size

1/2" 3-1/16 (78)

3/4" 3-5/8 (92)

ABC

4-5/8 (118) 1-3/4 (45)

Dimensions in Inches (mm)

1-1/4 (32) 1-11/16 (43)

1-3/4 (45)

(Stem Up)

1-1/8 (29) 7/16 (11)

(Stroke)

Figure-5 Typical of VB-7223-0-4-P Valve Bodies.

Page 12

F-26073-1

TAC

1354 Clifford Avenue P.O. Box 2940 Loves Park, IL 61132-2940

www.tac.com