TAC VB-7313 User Guide

Page 1

TAC

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

Application

VB-7313 series three-way mixing valves control hot or chilled water in heating or air conditioning systems. These valves must be piped with two inlets (“A” and “B” ports) and one outlet (“AB” port). 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-7313 series valve packings are not rated for combustible gas applications, and if used in these applications, gas leaks and explosions could result.

VB-7313 Series

1/2" to 2" Screwed NPT

Three-Way Mixing Valves

General Instructions

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-27414

• TAC Electric-Electronic Products Catalog, F-27382

• TAC Pneumatic Products Catalog, F-27383

• CA-28 Control Valve Sizing, F-13755

• Valve Selection Chart for Water, F-11080

• EN-205 Water System Guidelines, F-26080

• Vx-7xxx-8xx, Vx-7xxx-59x, Vx-9xxx-8xx,

Vx-9xxx-59x Globe Valve Assemblies with TAC DuraDrive Linear Series Actuators, F-26752

Page 2

SPECIFICATIONS

Table-1 Specifications/Models.

Specifications

Valve Body Series

VB-7313-0-4-P

Service Chilled or Hot Water

Flow Characteristics (Figure-1) Mixing

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 None

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

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

35 psi (241 kPa) Max. for Normal Life (refer to “Cavitation Limitations on Valve

Allowable Differential Pressure for Water

Pressure Drop” on page 6)

Valve S ize Cv Rating kvs Rating

1/2"

2.2 1.9 VB-7313-0-4-2

4.4 3.8 VB-7313-0-4-4

Complete Valve Body Part Number

3/4" 7.5 6.5 VB-7313-0-4-6

1" 14 12 VB-7313-0-4-8

1-1/4" 20 17 VB-7313-0-4-9

1-1/2" 28 24 VB-7313-0-4-10

2" 41 35 VB-7313-0-4-11

Do not apply above pressure rating to piping system.

Maximum recommended differential pressure. 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-27414, for close-off ratings.

Page 3

Spring Return Position of Valve Assembly

For a valve assembly (valve, linkage, and actuator) to have a 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 Spring Return Position

M400A, M800A, M1500A AV-811 (M1500 only) None

MA51-710x, MF51-7103, MS51-7103 Included with Actuator Stem Up

MA51-720x, MF51-7203, MS51-7203 Included with Actuator Stem Up

MA-318, MA-418, MA-419 AV-39 1 Stem Up or Down

MA-5210, MA-5211, MA-5213 AV-7600-1

MC-351, MC-431, MC-4311, MC5-4311 AV-39 3 None

MF-5413, MF-5513 AV-7600-1 & AV-601 Stem Up

MF-22203, MF-22303, MF-22323

MF-63103, MF-63123

MK-2690 AV-74 00

MK-6601, MK-6611, MK-6621 AV-43 0

MM-400, MMR-400

MM-500, MMR-500 Stem Up or Down

MP-361, MP-461-600, MP-465, MP5-4651

MP-371, MP-471-600, MP-475, MP5-4751 Stem Up

MP-381, MP-382, MP-481-600, MP-485, MP-486, MP-4851, MP5-4851

MP-5210, MP-5211, MP-5213 AV-7600-1

MP-5513

MPR-5610, MPR-5611, MPR-5613

MPR-5713

MS-22353 Included w/Actuator None

Stem Up = Flow port “B” to port “AB”. Stem Down = Flow port “A” to port “AB.”

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-7600-1 (F-26235) and AV-601 (F-19069) for details.

Included with Actuator None

AV-630 or

AV-630-10

AV-39 1

AV-39 3 None

AV-7600-1 & AV-601

AV-7600-1 & AV-601 Stem Up

Stem Up

Stem UpMK-4601, MK-4611, MK-4621 AV-40 1

None

Stem Down

Stem UpMP-5410, MP-5411, MP-5413

Flow Characteristics

Three-way mixing valves are designed so that the flow from either of the inlet ports to the outlet is approximately linear, which means the total flow from the outlet is almost constant over the stroke of the valve stem. See series valve bodies.

Figure-1 Typical Flow Characteristics.

Figure-1 for typical flow characteristics of VB-7313

Page 4

Rangeability

Rangeability is the ratio of rated flow to the minimum controllable flow through a valve. For mixing valves, control begins as soon as plug displacement allows flow. Thus, three-way valve rangeability normally exceeds 500:1, which is the reciprocal of 0.2% nominal leakage.

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-7313-0-4-P (Screwed Cast Bronze Body)

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

psig at 281°F

321 Materials: Bronze, ASTM B584

321 psig

(2218 kPa)

300 (149)

250 (121)

200 (93)

150 (65)

Maximum Fluid

Temperature

281¡F (138¡C)

100 (38)

TemperatureÑ¡F (¡C)

50 (10)

Minimum Fluid

Temperature

20¡F (-7¡C)

(345)

Figure-2 Temperature and Pressure Ratings

for VB-7313 Series Valve Bodies.

100

(689)

VB-7313-0-4-P

150

(1034)

PressureÑpsig (kPa)

200

(1379)

250

(1724)

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 to Bypass Flow

Proportional valves used to bypass flow (Figure-5) are piped on the outlet side of the load to throttle the water flow through the load and therefore control heat output of the load. These 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-3 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).

Ta bl e -3 ).

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).

Proportional to Blend Water Flows

Proportional valves used to blend two water flows (Figure-6 and Figure-7) control the heat output by varying the water temperature to the load at constant flow. These valves do not require high pressure drops for good control results. They can be sized for a pressure drop of 20% of the “available pressure” or equal to 25% of the pressure drop through the load at full flow.

Water Capacity

See Ta bl e -4 for water capacity of VB-7313 series valves.

Table-4 Water Capacity in Gallons Per Minute for VB-7313 Series.

Valve Body

Part Number

VB-7313-0-4-2 2.2 2.20 3.11 3.81 4.40 4.92 5.39 5.82 6.22 6.60 6.96 8.52 9.84 13.02

VB-7313-0-4-4 4.4 4.40 6.22 7.6 8.8 9.8 10.8 11. 6 12.4 13.2 13.9 17.0 19.7 26.0

VB-7313-0-4-6 7.5 8.0 11 .3 13.9 16.0 17.9 19.6 21.2 22.6 24.0 25.3 31.0 35.8 47

VB-7313-0-4-8 14 14 20 24 28 31 34 37 40 42 44 54 63 83

VB-7313-0-4-9 20 20 28 35 40 45 49 53 57 60 63 77 89 118

VB-7313-0-4-10 28 28 39 48 56 63 69 74 79 84 88 108 125 166

VB-7313-0-4-11 41 41 58 71 82 92 100 109 116 123 130 159 183 243

Rating

1 2 3 4 5 6 7 8 9 10 15 20 35

Differential Pressure (ΔP in psi)

Cv Equation

GPM

Cv=

ΔP

ΔP=

Where:

Cv= Coefficient of flow GPM = U.S. gallons per minute (60°F, 15.6°C)

ΔP= Differential pressure in psi (pressure drop)

GPM

()

GPM = Cv

ΔP

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.

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) P1= Absolute inlet pressure (psia) Pv = Absolute vapor pressure (psia) (refer to Table-5)

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-5 Vapor Pressure of Water Table.

Additional Valve Sizing Information

Water Tem p.

(°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

Vap or

Pressure

(psia)

Water Tem p.

(°F)

Vap or

Pressure

(psia)

Water Tem p.

(°F)

Vapor

Pressure

(psia)

Water Tem p.

(°F)

For additional valve sizing information, see:

• CA-28 Control Valve Sizing, F-13755

• Valve Selection Chart Water, F-11080

Vapor

Pressure

(psia)

Page 7

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 arrows (“A” and “B” ports are

inlets 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. The valves must be piped with two inlets (“A” and “B” ports) and one outlet (“AB” port).

Screwed Valve Bodies

The VB-7313-0-4-P 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. SeeTa bl e -6 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-6 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 8

Right Wrong

Pipe threads too long Pipe interferes with seat

Figure-3 Normal Thread Engagement.

Valve

Assembly

Use pipe wrench to prevent valve from turning.

Figure-4 Installation of Screwed End Valves.

Tighten pipe using this pipe wrench.

Page 9

TYPICAL PIPING

All piping must comply with local codes and ordinances. Refer to Figure-5 through Figure-7 for typical piping.

Valve

Coil

Return

Bypass

Supply Supply

Stem down flow through coil. Stem up flow through coil bypass.

Stem up flow through coil. Stem down flow through coil bypass.

Figure-5 Typical Piping for Control of Heating or Cooling Coil.

Val ve Assembly

Bypass

Supply

Bypass

Coil

System

Pump

Valve

Return

Boiler

Typical Boiler Hot Water Reset

Figure-6 Typical Boiler Hot Water Reset.

Coil

Balancing

Cock

Val ve Assembly

From Other

Zones

Return

Typical Primary-Secondary Piping

Balancing

Cock

To Other

Zones

Supply

Figure-7 Typical Primary-Secondary Piping.

Page 10

CHECKOUT

MAINTENANCE

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. Drive 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 shut off the “B” port.

b. Drive the actuator and valve to the stem up position. Again, the valve stem and

linkage should operate smoothly. At the stem up position, the valve should shut off the “A” port.

Regular maintenance of the total system is recommended to assure sustained performance. See Table-7 for maintenance kit part numbers.

Table-7 Maintenance Kits for VB-7313 Valves.

Water System Maintenance

Valve Body

Part Number

VB-7313-0-4-2

VB-7313-0-4-4 RYB-731-4

VB-7313-0-4-6 RYB-731-6

VB-7313-0-4-8 RYB-731-8

VB-7313-0-4-9 RYB-731-9

VB-7313-0-4-10 RYB-731-10

VB-7313-0-4-11 RYB-731-11

Kit includes replacement packing and stem & plug assembly.

Replacement

Packing Assembly

YBA-622-2 TOOL-20-1

Packing Wrench Valve Repair Kit

RYB-731-2

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-8 Dimensions for VB-7313 Series Valves (Figure-8).

Part

Number

VB-7313-0-4-2 VB-7313-0-4-4

VB-7313-0-4-6 3/4" 3-5/8 (92) 1-11/16 (43)

VB-7313-0-4-8 1"

VB-7313-0-4-9 1-1/4" 1-13/16 (46) 2 (51)

VB-7313-0-4-10 1-1/2" 5-3/8 (137) 1-5/8 (41) 1-1/8 (29)

VB-7313-0-4-11 2" 6-1/8 (156) 1-7/8 (48) 1-3/16 (30)

Valve

Size

1/2" 3 (76) 1-3/8 (35)

A B C

4-5/8 (117)

Dimensions in Inches (mm)

1-11/16 (43)

1-9/16 (40) 1-3/4 (45)

(Stem Down)E(Stroke)

3/4 (19) 7/16 (11)

Figure-8 Typical of VB-7313-0-4-P Valve Bodies.

Page 12

F-26074-2

TAC

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

www.tac.com