Valves

Diaphragm Valves

Available Series

11 Series Available

Select a series to view detailed specifications, dimensional drawings, and ordering information.

Standard UHP Manual Diaphragm ValveUHP
DV-01

Standard UHP Manual Diaphragm Valve

Springless hard-metal diaphragm seal for ultra-high purity semiconductor gas service. Low and high pressure variants in a single series.

Working pressure (LP)
Vacuum to 300 PSI (20.7 bar)
Working pressure (HP)
Vacuum to 3000 PSI (207 bar)
Burst pressure
LP 900 PSI / HP 9000 PSI
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Pneumatic NC/NO Diaphragm ValveUHP
DV-02

Pneumatic NC/NO Diaphragm Valve

Fast, repeatable pneumatic actuation with hard-metal diaphragm seal for UHP semiconductor gas service.

Working pressure (LP)
Vacuum to 150 PSI (10.3 bar)
Working pressure (HP)
Vacuum to 2200 PSI (152 bar)
Burst pressure
LP 450 PSI / HP 6600 PSI
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Manual Diaphragm Valve with Status Indicator & LOTOUHP
DV-03

Manual Diaphragm Valve with Status Indicator & LOTO

Visual open/close status indicator and optional LOTO lockout for safety-critical UHP gas isolation points.

Working pressure
Vacuum to 300 PSI (20.7 bar)
Burst pressure
900 PSI
Flow coefficient (Cv)
0.5
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High-Pressure Small-Flow Diaphragm Valve —DV4 SeriesHP
DV-04

High-Pressure Small-Flow Diaphragm Valve —DV4 Series

High-pressure small-flow diaphragm valve for ultra-high purity applications. GP/HP/UHP three process grades available.

Bore diameter
4.1 mm (0.16 in.)
Port size
1/4" to 3/8", 6 mm to 8 mm
Flow coefficient (Cv)
0.26
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High-Pressure Medium-Flow Diaphragm Valve —DV5 SeriesHP
DV-05

High-Pressure Medium-Flow Diaphragm Valve —DV5 Series

High-pressure medium-flow diaphragm valve for ultra-high purity applications. Spring-loaded design. GP/HP/UHP three process grades available.

Bore diameter
7.5 mm (0.3 in.)
Port size
3/8" to 1/2", 10 mm to 12 mm
Flow coefficient (Cv)
0.8
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Medium-Pressure Medium-Flow Diaphragm Valve —DV6 SeriesHP
DV-06

Medium-Pressure Medium-Flow Diaphragm Valve —DV6 Series

Medium-pressure medium-flow diaphragm valve for ultra-high purity applications. No internal threads or springs. GP/HP/UHP three process grades available.

Bore diameter
6 mm (0.24 in.)
Port size
3/8" to 1/2", 10 mm to 12 mm
Flow coefficient (Cv)
0.65
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High-Pressure Spring-Return Diaphragm Valve —DV7 SeriesHP
DV-07

High-Pressure Spring-Return Diaphragm Valve —DV7 Series

High-pressure spring-return diaphragm valve. Spring-return stem allows full operation under vacuum conditions. GP/HP/UHP three process grades available.

Bore diameter
4.1 mm (0.16 in.)
Port size
1/4" to 3/8", 6 mm to 8 mm
Flow coefficient (Cv) —bar handle
0.14
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Atomic Layer Deposition Diaphragm Valve —ALD SeriesUHP
DV-08

Atomic Layer Deposition Diaphragm Valve —ALD Series

Ultra-fast ALD valve for atomic layer deposition. <15 ms response, PFA seat, up to 200 °C.

Bore diam. (small)
4.1 mm (0.16 in.)
Bore diam. (large)
5.9 mm (0.23 in.)
Cv (small bore)
0.27
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Low-Pressure Small-Flow Diaphragm Valve —DV1 SeriesHP
DV-09

Low-Pressure Small-Flow Diaphragm Valve —DV1 Series

Low-pressure small-flow, Cv 0.3, up to 250 psig. Compact design, PCTFE or PFA seat. Manual or pneumatic.

Bore diameter
4.1 mm (0.16 in.)
Port size
1/4" to 3/8", 6 mm to 8 mm
Flow coefficient (Cv)
0.3
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Low-Pressure Medium-Flow Diaphragm Valve —DV2 SeriesHP
DV-10

Low-Pressure Medium-Flow Diaphragm Valve —DV2 Series

Low-pressure medium-flow, Cv 0.65, up to 250 psig. 6 mm bore, pneumatic or manual.

Bore diameter
6 mm (0.24 in.)
Port size
3/8" to 1/2", 10 mm to 12 mm
Flow coefficient (Cv)
0.65
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Low-Pressure High-Flow Diaphragm Valve —DV3 SeriesHP
DV-11

Low-Pressure High-Flow Diaphragm Valve —DV3 Series

Low-pressure large-flow diaphragm valve, Cv 2.8, 10.2 mm bore. Tied-diaphragm, 1/2" to 1" ports.

Bore diameter
10.2 mm (0.4 in.)
Port size
1/2", 3/4", 1"
Flow coefficient (Cv)
2.8
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Applications
  • Semiconductor fab gas stick isolation
  • Specialty gas panel point-of-use
  • Bulk gas distribution headers
  • Process gas manifolds
Gas Service
N₂ArHeH₂NH₂HClSiH₂WF₆BCl₃
FAQ

Frequently Asked Questions

What diaphragm materials are available and how do I choose between Co-Ni alloy and Hastelloy C-22?

Co-Ni alloy diaphragms are the standard choice for most UHP semiconductor gases including N₂, Ar, He, and H₂, offering a balance of cycle life and corrosion resistance. Hastelloy C-22 diaphragms are specified for highly corrosive chemistries such as HCl, WF₆, BCl₃, and halogen-bearing gases where Co-Ni alloy may suffer accelerated fatigue. Consult the gas compatibility chart in the product datasheet and specify Hastelloy C-22 whenever the process gas has a chloride, fluoride, or strong oxidizer component.

What is the rated cycle life for KTIC diaphragm valves, and what factors shorten it?

Standard UHP diaphragm valves are rated for ≥150,000 full open/close cycles at the nominal operating pressure. Cycle life is reduced by operating above the rated pressure, by large ΔP across the diaphragm during actuation, by elevated temperatures above 85 °C, and by chemical attack on the diaphragm material. Pneumatic actuation with controlled supply pressure and gentle seating force extends service life compared to manual operation with excessive torque.

Is Hastelloy C-22 the required standard for all corrosive-gas diaphragm valves, or are there alternatives?

Hastelloy C-22 is the most common high-corrosion choice and is stocked in all standard port sizes. For ultra-high-purity fluorine or ClF₃ service, Monel 400 or nickel-body valves may be required instead. For moderate corrosion at lower pressures, PVDF-lined body options exist. Always cross-reference the specific gas, concentration, temperature, and pressure against the manufacturer's compatibility table before selecting a diaphragm/body combination.

How should VCR face-seal fittings be installed on diaphragm valve ports to ensure leak-tight connections?

VCR face-seal connections require a fresh silver-plated or stainless retainer gasket for every assembly. Clean all mating surfaces with IPA and inspect for scratches under magnification before assembly. Finger-tighten the nut until snug, then advance 1/8 turn (UHP) or 1/4 turn (standard) with a calibrated torque wrench — typically 100–125 in-lb for 1/4" and 200–225 in-lb for 1/2". Never re-use a compressed gasket. After assembly, perform a helium leak check to ≤1×10⁻⁹ atm·cc/s before pressurizing with process gas.

What is the correct purge procedure for diaphragm valves before introducing a reactive or toxic process gas?

Perform a minimum of five pressure-cycle purges using dry N₂ or Ar at the system's rated pressure. With the valve closed, pressurize the upstream side, then open the valve to purge through the downstream vent. For pyrophoric or highly toxic gases (WF₆, BCl₃), extend to ten purge cycles and verify residual moisture below 1 ppb with an inline moisture monitor before switching to process gas. Document purge cycle count, pressure, and moisture readings in the maintenance log.

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