Instrumentation Valves
Instrumentation valves provide precise fluid control for measurement, sampling, and process control systems. Shop instrumentation solenoid valves for automated on/off switching in...
Categories in Valves - Efficient Flow Control Solutions (1)
Instrumentation Needle Valves
Needle valves are precision valves used for flow control in low-flow applications or systems requiring fine adjustment. They feature a slender, tapered needle-like plunger that can be raised or lowered to regulate the flow through a small orifice. Needle valves provide accurate and precise control of flow rates, making them ideal for applications where flow modulation is critical, such as laboratory equipment, analytical instruments, or hydraulic systems. They offer reliable shut-off capabilities and precise flow adjustment, ensuring optimal performance and efficiency.
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The Dwyer - SV6005-NO is a Solenoid Valve featuring OMEGA-FLO, 2-Way, N.O, Pilot Operated, 1 ", 14.0 Cv, AC/DC Coil, Brass Body, SS, Copper, Buna, AC 230 psi, DC 230 psi, Liquid, and Gas. It is rated for a temperature range of 90 °C (195 °F). Part of the SV6000 Series. Sold individually.
$434.58
Should ship between 13 Nov and 20 Nov
Subject to factory lead times
The Dwyer - SV6006 is a Solenoid Valve featuring OMEGA-FLO, 2-Way, N.C, Pilot Operated, 1-1/4 ", 28.0 Cv, AC/DC Coil, Brass Body, SS, Copper, Buna, AC 150 psi, DC 150 psi, Liquid, and Gas. It is rated for a temperature range of 90 °C (195 °F). Part of the SV6000 Series. Sold individually.
$714.03
Should ship between 06 Nov and 13 Nov
Subject to factory lead times
The Dwyer - SV6007 is a Solenoid Valve featuring OMEGA-FLO, 2-Way, N.C, Pilot Operated, 1-1/2 ", 36.0 Cv, AC/DC Coil, Brass Body, SS, Copper, Buna, AC 150 psi, DC 150 psi, Liquid, and Gas. It is rated for a temperature range of 90 °C (195 °F). Part of the SV6000 Series. Sold individually.
$798.49
Should ship between 06 Nov and 13 Nov
Subject to factory lead times
The Dwyer - SV6103A is a Solenoid Valve featuring 2-Way, N.C, Pilot Operated, 1/2 ", 4.8 Cv, AC/DC Coil, Lead-Free Brass Body, SS, Copper, EPDM, 230 psi, Liquid, and Gas. It is rated for a temperature range of 137 °C (280 °F). Part of the SV6100A Series. Sold individually.
$345.22
Should ship between 06 Nov and 13 Nov
Subject to factory lead times
The Dwyer - SV6107 is a Solenoid Valve featuring 2-Way, N.C, Pilot Operated, 1-1/2 ", 36.0 Cv, AC/DC Coil, Brass Body, SS, Copper, FKM, 150 psi, Liquid, and Gas. It is rated for a temperature range of 137 °C (280 °F). Part of the SV6100 Series. Sold individually.
$806.90
Should ship between 06 Nov and 13 Nov
Subject to factory lead times
The Dwyer - SVH-111-NO is a Solenoid Valve featuring High Pressure, 2-Way, N.O, Direct Acting, 1/4 ", 0.005 Cv, 120 Vac, 316 SS Body, 300 SS, 430 SS, FEP, 10000 psi, Liquid, and Gas. It is rated for a temperature range of 204 °C (400 °F). Part of the SVH-111 Series. Sold individually.
$1,337.30
Should ship between 13 Nov and 20 Nov
Subject to factory lead times
The Dwyer - SVH-112-24D is a Solenoid Valve featuring High Pressure, 2-Way, N.C, Direct Acting, 1/4 ", 0.02 Cv, 24 Vdc, 316 SS Body, 300 SS, 430 SS, FEP, 2000 psi, Liquid, and Gas. It is rated for a temperature range of 204 °C (400 °F). Part of the SVH-112 Series. Sold individually.
$1,110.64
Should ship between 13 Nov and 20 Nov
Subject to factory lead times
The Dwyer - SVH-112-NO is a Solenoid Valve featuring High Pressure, 2-Way, N.O, Direct Acting, 1/4 ", 0.02 Cv, 120 Vac, 316 SS Body, 300 SS, 430 SS, FEP, 4000 psi, Liquid, and Gas. It is rated for a temperature range of 204 °C (400 °F). Part of the SVH-112 Series. Sold individually.
$1,277.62
Should ship between 13 Nov and 20 Nov
Subject to factory lead times
The Dwyer - SVH-121-24A is a Solenoid Valve featuring High Pressure, 2-Way, N.C, Direct Acting, 1/4 ", 1.1 Cv, 24 Vac, 316 SS Body, 300 SS, 430 SS, PEAK, Buna, FKM, PTFE, Nylon, 7, 500 psi, Liquid, and Gas. It is rated for a temperature range of 121 °C. Part of the SVH-120 Series. Sold individually.
$1,451.14
Should ship between 13 Nov and 20 Nov
Subject to factory lead times
The Dwyer - SVH-122-NO is a Solenoid Valve featuring High Pressure, 2-Way, N.O, Direct Acting, 1/2 ", 4.5 Cv, 120 Vac, 316 SS Body, 300 SS, 430 SS, PEAK, Buna, FKM, PTFE, Nylon, 5000 psi, Liquid, and Gas. It is rated for a temperature range of 121 °C. Part of the SVH-120 Series. Sold individually.
$1,771.10
Should ship between 13 Nov and 20 Nov
Subject to factory lead times
The Dwyer - SVH-141L-24D is a Solenoid Valve featuring High Pressure, 2-Way, N.C, Direct Acting, 1/2 ", 3.5 Cv, 24 Vdc, 316 SS Body, 300 SS, 430 SS, PTFE, 1, 500 psi, and Liquid. It is rated for a temperature range of 149 °C (300 °F). Part of the SVH-140 Series. Sold individually.
$2,182.03
Should ship between 13 Nov and 20 Nov
Subject to factory lead times
The Dwyer - SVH-142L-24D is a Solenoid Valve featuring High Pressure, 2-Way, N.C, Direct Acting, 3/4 ", 7.5 Cv, 24 Vdc, 316 SS Body, 300 SS, 430 SS, PTFE, 1, 200 psi, and Liquid. It is rated for a temperature range of 149 °C (300 °F). Part of the SVH-140 Series. Sold individually.
$2,414.61
Should ship between 13 Nov and 20 Nov
Subject to factory lead times
The Dwyer - SVH-143L-24D is a Solenoid Valve featuring High Pressure, 2-Way, N.C, Direct Acting, 1 ", 13 Cv, 24 Vdc, 316 SS Body, 300 SS, 430 SS, PTFE, 1, 200 psi, and Liquid. It is rated for a temperature range of 149 °C (300 °F). Part of the SVH-140 Series. Sold individually.
$2,605.33
Should ship between 13 Nov and 20 Nov
Subject to factory lead times
Hoke NEEDLE VALVE;1/2 GYROLOK ENDS, 5000PS
Requires Quote
Should ship between 30 Oct and 06 Nov
Subject to factory lead times
Configure product to see pricing
The Truflo BRP Series Back Pressure Relief Valve has two functions. As a back pressure valve installed in-line downstream of a pump. In this position the back pressure below the metering pump is maintained. When the BRP Valve is installed in the branch of a tee fitting it functions as a pressure relief valve. The valve remains closed until inlet pressure reaches the preset pressure which is adjusted by turning the spring tension bolt. The pressure as the inlet of the valve acts upward against the piston allowing the liquid under higher pressure to flow upwards through the orifice.
Configure Product
Configure product to see pricing
735/740 Series Needle Valves are of the rising stem type and are designed to shut off the flow of the process media to the pressure instrument, thereby allowing the instrument to be isolated from the pressure media or removed from service. Needle valves may also be used to throttle flow and aid in dampening pulsations. Trerice Needle Valves are constructed from brass, carbon steel and stainless steel for use on a variety of pressure media. It is recommended to place a needle valve, ball valve or gauge cock in line before every pressure gauge installation.
$8.36$14.50
In Stock (6219)Ships within 1 business day
735/740 Series Needle Valves are of the rising stem type and are designed to shut off the flow of the process media to the pressure instrument, thereby allowing the instrument to be isolated from the pressure media or removed from service. Needle valves may also be used to throttle flow and aid in dampening pulsations. Trerice Needle Valves are constructed from brass, carbon steel and stainless steel for use on a variety of pressure media. It is recommended to place a needle valve, ball valve or gauge cock in line before every pressure gauge installation.
$16.28$28.25
In Stock (2753)Ships within 1 business day
735/740 Series Needle Valves are of the rising stem type and are designed to shut off the flow of the process media to the pressure instrument, thereby allowing the instrument to be isolated from the pressure media or removed from service. Needle valves may also be used to throttle flow and aid in dampening pulsations. Trerice Needle Valves are constructed from brass, carbon steel and stainless steel for use on a variety of pressure media. It is recommended to place a needle valve, ball valve or gauge cock in line before every pressure gauge installation.
$53.14$92.25
In Stock (67)Ships within 1 business day
735/740 Series Needle Valves are of the rising stem type and are designed to shut off the flow of the process media to the pressure instrument, thereby allowing the instrument to be isolated from the pressure media or removed from service. Needle valves may also be used to throttle flow and aid in dampening pulsations. Trerice Needle Valves are constructed from brass, carbon steel and stainless steel for use on a variety of pressure media. It is recommended to place a needle valve, ball valve or gauge cock in line before every pressure gauge installation.
$119.81$208.00
In Stock (5263)Ships within 1 business day
735/740 Series Needle Valves are of the rising stem type and are designed to shut off the flow of the process media to the pressure instrument, thereby allowing the instrument to be isolated from the pressure media or removed from service. Needle valves may also be used to throttle flow and aid in dampening pulsations. Trerice Needle Valves are constructed from brass, carbon steel and stainless steel for use on a variety of pressure media. It is recommended to place a needle valve, ball valve or gauge cock in line before every pressure gauge installation.
$119.81$208.00
In Stock (668)Ships within 1 business day
735/740 Series Needle Valves are of the rising stem type and are designed to shut off the flow of the process media to the pressure instrument, thereby allowing the instrument to be isolated from the pressure media or removed from service. Needle valves may also be used to throttle flow and aid in dampening pulsations. Trerice Needle Valves are constructed from brass, carbon steel and stainless steel for use on a variety of pressure media. It is recommended to place a needle valve, ball valve or gauge cock in line before every pressure gauge installation.
$126.72$220.00
In Stock (826)Ships within 1 business day
735/740 Series Needle Valves are of the rising stem type and are designed to shut off the flow of the process media to the pressure instrument, thereby allowing the instrument to be isolated from the pressure media or removed from service. Needle valves may also be used to throttle flow and aid in dampening pulsations. Trerice Needle Valves are constructed from brass, carbon steel and stainless steel for use on a variety of pressure media. It is recommended to place a needle valve, ball valve or gauge cock in line before every pressure gauge installation.
$56.45$98.00
In Stock (613)Ships within 1 business day
735/740 Series Needle Valves are of the rising stem type and are designed to shut off the flow of the process media to the pressure instrument, thereby allowing the instrument to be isolated from the pressure media or removed from service. Needle valves may also be used to throttle flow and aid in dampening pulsations. Trerice Needle Valves are constructed from brass, carbon steel and stainless steel for use on a variety of pressure media. It is recommended to place a needle valve, ball valve or gauge cock in line before every pressure gauge installation.
$126.72$220.00
In Stock (295)Ships within 1 business day
The WIKA 910.11 hard-seat needle valve / pressure gauge valve in stainless steel with 1/4 NPT connections provides positive shut-off and venting for gauge isolation and calibration duties. Its hard-seat design ensures bubble-tight closure and long service life in high-pressure gas and liquid service across process, petrochemical, and power generation applications.
$34.19$52.92
Quick Ship
Ships in 24 hours - order by 2pm EDT
The Dwyer - SV6005-NO is a Solenoid Valve featuring OMEGA-FLO, 2-Way, N.O, Pilot Operated, 1 ", 14.0 Cv, AC/DC Coil, Brass Body, SS, Copper, Buna, AC 230 psi, DC 230 psi, Liquid, and Gas. It is rated for a temperature range of 90 °C (195 °F). Part of the SV6000 Series. Sold individually.
$434.58
Should ship between 13 Nov and 20 Nov
Subject to factory lead times
The Dwyer - SV6006 is a Solenoid Valve featuring OMEGA-FLO, 2-Way, N.C, Pilot Operated, 1-1/4 ", 28.0 Cv, AC/DC Coil, Brass Body, SS, Copper, Buna, AC 150 psi, DC 150 psi, Liquid, and Gas. It is rated for a temperature range of 90 °C (195 °F). Part of the SV6000 Series. Sold individually.
$714.03
Should ship between 06 Nov and 13 Nov
Subject to factory lead times
The Dwyer - SV6007 is a Solenoid Valve featuring OMEGA-FLO, 2-Way, N.C, Pilot Operated, 1-1/2 ", 36.0 Cv, AC/DC Coil, Brass Body, SS, Copper, Buna, AC 150 psi, DC 150 psi, Liquid, and Gas. It is rated for a temperature range of 90 °C (195 °F). Part of the SV6000 Series. Sold individually.
$798.49
Should ship between 06 Nov and 13 Nov
Subject to factory lead times
The Dwyer - SV6103A is a Solenoid Valve featuring 2-Way, N.C, Pilot Operated, 1/2 ", 4.8 Cv, AC/DC Coil, Lead-Free Brass Body, SS, Copper, EPDM, 230 psi, Liquid, and Gas. It is rated for a temperature range of 137 °C (280 °F). Part of the SV6100A Series. Sold individually.
$345.22
Should ship between 06 Nov and 13 Nov
Subject to factory lead times
The Dwyer - SV6107 is a Solenoid Valve featuring 2-Way, N.C, Pilot Operated, 1-1/2 ", 36.0 Cv, AC/DC Coil, Brass Body, SS, Copper, FKM, 150 psi, Liquid, and Gas. It is rated for a temperature range of 137 °C (280 °F). Part of the SV6100 Series. Sold individually.
$806.90
Should ship between 06 Nov and 13 Nov
Subject to factory lead times
The Dwyer - SVH-111-NO is a Solenoid Valve featuring High Pressure, 2-Way, N.O, Direct Acting, 1/4 ", 0.005 Cv, 120 Vac, 316 SS Body, 300 SS, 430 SS, FEP, 10000 psi, Liquid, and Gas. It is rated for a temperature range of 204 °C (400 °F). Part of the SVH-111 Series. Sold individually.
$1,337.30
Should ship between 13 Nov and 20 Nov
Subject to factory lead times
The Dwyer - SVH-112-24D is a Solenoid Valve featuring High Pressure, 2-Way, N.C, Direct Acting, 1/4 ", 0.02 Cv, 24 Vdc, 316 SS Body, 300 SS, 430 SS, FEP, 2000 psi, Liquid, and Gas. It is rated for a temperature range of 204 °C (400 °F). Part of the SVH-112 Series. Sold individually.
$1,110.64
Should ship between 13 Nov and 20 Nov
Subject to factory lead times
The Dwyer - SVH-112-NO is a Solenoid Valve featuring High Pressure, 2-Way, N.O, Direct Acting, 1/4 ", 0.02 Cv, 120 Vac, 316 SS Body, 300 SS, 430 SS, FEP, 4000 psi, Liquid, and Gas. It is rated for a temperature range of 204 °C (400 °F). Part of the SVH-112 Series. Sold individually.
$1,277.62
Should ship between 13 Nov and 20 Nov
Subject to factory lead times
The Dwyer - SVH-121-24A is a Solenoid Valve featuring High Pressure, 2-Way, N.C, Direct Acting, 1/4 ", 1.1 Cv, 24 Vac, 316 SS Body, 300 SS, 430 SS, PEAK, Buna, FKM, PTFE, Nylon, 7, 500 psi, Liquid, and Gas. It is rated for a temperature range of 121 °C. Part of the SVH-120 Series. Sold individually.
$1,451.14
Should ship between 13 Nov and 20 Nov
Subject to factory lead times
The Dwyer - SVH-122-NO is a Solenoid Valve featuring High Pressure, 2-Way, N.O, Direct Acting, 1/2 ", 4.5 Cv, 120 Vac, 316 SS Body, 300 SS, 430 SS, PEAK, Buna, FKM, PTFE, Nylon, 5000 psi, Liquid, and Gas. It is rated for a temperature range of 121 °C. Part of the SVH-120 Series. Sold individually.
$1,771.10
Should ship between 13 Nov and 20 Nov
Subject to factory lead times
The Dwyer - SVH-141L-24D is a Solenoid Valve featuring High Pressure, 2-Way, N.C, Direct Acting, 1/2 ", 3.5 Cv, 24 Vdc, 316 SS Body, 300 SS, 430 SS, PTFE, 1, 500 psi, and Liquid. It is rated for a temperature range of 149 °C (300 °F). Part of the SVH-140 Series. Sold individually.
$2,182.03
Should ship between 13 Nov and 20 Nov
Subject to factory lead times
The Dwyer - SVH-142L-24D is a Solenoid Valve featuring High Pressure, 2-Way, N.C, Direct Acting, 3/4 ", 7.5 Cv, 24 Vdc, 316 SS Body, 300 SS, 430 SS, PTFE, 1, 200 psi, and Liquid. It is rated for a temperature range of 149 °C (300 °F). Part of the SVH-140 Series. Sold individually.
$2,414.61
Should ship between 13 Nov and 20 Nov
Subject to factory lead times
The Dwyer - SVH-143L-24D is a Solenoid Valve featuring High Pressure, 2-Way, N.C, Direct Acting, 1 ", 13 Cv, 24 Vdc, 316 SS Body, 300 SS, 430 SS, PTFE, 1, 200 psi, and Liquid. It is rated for a temperature range of 149 °C (300 °F). Part of the SVH-140 Series. Sold individually.
$2,605.33
Should ship between 13 Nov and 20 Nov
Subject to factory lead times
Hoke NEEDLE VALVE;1/2 GYROLOK ENDS, 5000PS
Requires Quote
Should ship between 30 Oct and 06 Nov
Subject to factory lead times
Configure product to see pricing
The Truflo BRP Series Back Pressure Relief Valve has two functions. As a back pressure valve installed in-line downstream of a pump. In this position the back pressure below the metering pump is maintained. When the BRP Valve is installed in the branch of a tee fitting it functions as a pressure relief valve. The valve remains closed until inlet pressure reaches the preset pressure which is adjusted by turning the spring tension bolt. The pressure as the inlet of the valve acts upward against the piston allowing the liquid under higher pressure to flow upwards through the orifice.
Configure Product
Configure product to see pricing
735/740 Series Needle Valves are of the rising stem type and are designed to shut off the flow of the process media to the pressure instrument, thereby allowing the instrument to be isolated from the pressure media or removed from service. Needle valves may also be used to throttle flow and aid in dampening pulsations. Trerice Needle Valves are constructed from brass, carbon steel and stainless steel for use on a variety of pressure media. It is recommended to place a needle valve, ball valve or gauge cock in line before every pressure gauge installation.
$8.36$14.50
In Stock (6219)Ships within 1 business day
735/740 Series Needle Valves are of the rising stem type and are designed to shut off the flow of the process media to the pressure instrument, thereby allowing the instrument to be isolated from the pressure media or removed from service. Needle valves may also be used to throttle flow and aid in dampening pulsations. Trerice Needle Valves are constructed from brass, carbon steel and stainless steel for use on a variety of pressure media. It is recommended to place a needle valve, ball valve or gauge cock in line before every pressure gauge installation.
$16.28$28.25
In Stock (2753)Ships within 1 business day
735/740 Series Needle Valves are of the rising stem type and are designed to shut off the flow of the process media to the pressure instrument, thereby allowing the instrument to be isolated from the pressure media or removed from service. Needle valves may also be used to throttle flow and aid in dampening pulsations. Trerice Needle Valves are constructed from brass, carbon steel and stainless steel for use on a variety of pressure media. It is recommended to place a needle valve, ball valve or gauge cock in line before every pressure gauge installation.
$53.14$92.25
In Stock (67)Ships within 1 business day
735/740 Series Needle Valves are of the rising stem type and are designed to shut off the flow of the process media to the pressure instrument, thereby allowing the instrument to be isolated from the pressure media or removed from service. Needle valves may also be used to throttle flow and aid in dampening pulsations. Trerice Needle Valves are constructed from brass, carbon steel and stainless steel for use on a variety of pressure media. It is recommended to place a needle valve, ball valve or gauge cock in line before every pressure gauge installation.
$119.81$208.00
In Stock (5263)Ships within 1 business day
735/740 Series Needle Valves are of the rising stem type and are designed to shut off the flow of the process media to the pressure instrument, thereby allowing the instrument to be isolated from the pressure media or removed from service. Needle valves may also be used to throttle flow and aid in dampening pulsations. Trerice Needle Valves are constructed from brass, carbon steel and stainless steel for use on a variety of pressure media. It is recommended to place a needle valve, ball valve or gauge cock in line before every pressure gauge installation.
$119.81$208.00
In Stock (668)Ships within 1 business day
735/740 Series Needle Valves are of the rising stem type and are designed to shut off the flow of the process media to the pressure instrument, thereby allowing the instrument to be isolated from the pressure media or removed from service. Needle valves may also be used to throttle flow and aid in dampening pulsations. Trerice Needle Valves are constructed from brass, carbon steel and stainless steel for use on a variety of pressure media. It is recommended to place a needle valve, ball valve or gauge cock in line before every pressure gauge installation.
$126.72$220.00
In Stock (826)Ships within 1 business day
735/740 Series Needle Valves are of the rising stem type and are designed to shut off the flow of the process media to the pressure instrument, thereby allowing the instrument to be isolated from the pressure media or removed from service. Needle valves may also be used to throttle flow and aid in dampening pulsations. Trerice Needle Valves are constructed from brass, carbon steel and stainless steel for use on a variety of pressure media. It is recommended to place a needle valve, ball valve or gauge cock in line before every pressure gauge installation.
$56.45$98.00
In Stock (613)Ships within 1 business day
735/740 Series Needle Valves are of the rising stem type and are designed to shut off the flow of the process media to the pressure instrument, thereby allowing the instrument to be isolated from the pressure media or removed from service. Needle valves may also be used to throttle flow and aid in dampening pulsations. Trerice Needle Valves are constructed from brass, carbon steel and stainless steel for use on a variety of pressure media. It is recommended to place a needle valve, ball valve or gauge cock in line before every pressure gauge installation.
$126.72$220.00
In Stock (295)Ships within 1 business day
The WIKA 910.11 hard-seat needle valve / pressure gauge valve in stainless steel with 1/4 NPT connections provides positive shut-off and venting for gauge isolation and calibration duties. Its hard-seat design ensures bubble-tight closure and long service life in high-pressure gas and liquid service across process, petrochemical, and power generation applications.
$34.19$52.92
Quick Ship
Ships in 24 hours - order by 2pm EDT
FAQS
- Instrumentation and process control valves regulate, isolate, and direct the flow of fluids in industrial piping systems. The main types include ball valves (quarter-turn valves for quick on/off isolation with low pressure drop), globe valves (linear-motion valves designed for precise throttling and flow control), butterfly valves (compact quarter-turn valves for larger pipe sizes), gate valves (full-bore isolation valves for minimal pressure drop when fully open), check valves (prevent reverse flow to protect pumps and equipment), needle valves (fine-adjustment valves for instrument tubing and low-flow applications), diaphragm valves (isolate the process fluid from the valve mechanism — ideal for corrosive, abrasive, or sanitary applications), and plug valves (robust quarter-turn valves for dirty or viscous service). Each type is available in a range of materials, sizes, and pressure ratings to match specific process conditions.
- The choice depends on the function you need the valve to perform. A ball valve is the best choice for quick on/off isolation — it opens and closes with a 90° turn of the handle, provides a full-bore flow path with minimal pressure drop when open, and seals tightly when closed. Use a ball valve when you need to fully open or fully close a line and don't need to control flow at intermediate positions. A globe valve is designed for throttling and flow control — its linear-motion plug can be positioned at any point between fully open and fully closed to regulate flow rate precisely. Use a globe valve when you need to modulate flow to a setpoint, especially in control valve applications with actuators and positioners. A butterfly valve is the most compact and lightweight option for larger pipe sizes (4" and above) — it uses a rotating disc to control flow and is commonly used in water, HVAC, and general process applications. Butterfly valves cost less than ball or globe valves in larger sizes but are not as tight-sealing for critical isolation.
- A control valve is an automated valve that continuously adjusts its position in response to a signal from a controller (PLC, DCS, or standalone controller) to regulate a process variable — flow rate, pressure, temperature, or level. It consists of the valve body (typically a globe, ball, or butterfly type), an actuator (pneumatic, electric, or hydraulic that moves the valve to the commanded position), and often a positioner (an intelligent device that compares the controller's signal to the valve's actual position and makes corrections for precision). A manual valve, by contrast, is positioned by hand using a handwheel, lever, or gear operator — it stays wherever the operator sets it and does not adjust automatically. Use a control valve when the process requires continuous, automatic regulation. Use a manual valve for isolation (fully open or fully closed) and for applications where occasional manual adjustment is sufficient.
- Cv (valve flow coefficient) is a standardized number that quantifies how much fluid a valve can pass at a given pressure drop. Specifically, a Cv of 1 means the valve will pass 1 gallon per minute of water at a pressure drop of 1 psi across the valve. A higher Cv means the valve can pass more flow. Cv matters because it is the primary tool for matching the valve size to your process flow requirements — if you select a valve with too low a Cv, it won't be able to pass enough flow even when fully open; if you select a valve with too high a Cv, it will operate mostly near the closed position, making precise control difficult and accelerating wear. To size a valve correctly, calculate the required Cv using your process flow rate, fluid properties (specific gravity, viscosity), and the available pressure drop across the valve, then select a valve model whose Cv range brackets the calculated value with the valve operating between 20% and 80% open at normal conditions.
- Valve material selection must match the fluid chemistry, temperature, and pressure. For general non-corrosive service (water, air, oil), carbon steel or ductile iron bodies with standard trim are cost-effective and widely used. For corrosive chemicals, acids, and caustics, stainless steel (316SS) is the standard upgrade — it resists a wide range of corrosive media and handles moderate temperatures. For highly corrosive environments (concentrated acids, chloride-rich media, bleach), specialty alloys like Hastelloy C, Monel, or titanium may be required. For sanitary applications (food, beverage, pharmaceutical), 316L stainless steel with electropolished surfaces and FDA-compliant elastomers is standard. For high-temperature service (steam, thermal oil, hot gas), the body material must maintain strength at temperature — carbon steel is good to about 800°F, stainless steel to about 1,000°F, and specialty alloys beyond that. Seat and seal materials are equally critical — PTFE seats handle most chemicals but are limited to about 450°F; metal seats handle higher temperatures; elastomers like Viton, EPDM, and Kalrez are selected based on chemical compatibility.