6.00" Gate Valve, UHV, Pneumatic, Del-Seal CF ConFlat Port Flange, UNF Thread, Copper Bonnet Seal, 300 SS

Part Number / SKU
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Vacuum gate valves are devices that regulate the flow of gases, fluids or materials through a structure or aperture by opening, closing or obstructing aport or passageway. Gate valve assemblies consist of three key components:

  • an actuator
  • a carriage/gate
  • a valve body

The actuator provides the power to position or transport the valve's carriage/gate. The actuator is attached to the valve's body via a rectangular bonnet flange. The gate closes or opens one of the valve's body ports. The valve body is a vacuum tight chamber that is screwed, flanged or welded into a larger vacuum vessel or system.

Reliable vacuum valves were not commercially available until the late1940s with the advent of O-ring elastomer seals. An O-ring, also known as a packing or a toric joint, is a mechanical gasket in the shape of a torus; it is a loop of elastomer with a round cross-section, designed to be seated in a groove and compressed during assembly between two or more parts, forming a seal at the interface. Developed during WWII for use in aircraft hydraulic systems, the elastomer O-ring was soon thereafter adopted by the vacuum community as the standard means of making vacuum seals. Prior to this, it was common practice, even in large research establishments, to upgrade general service valves for vacuum use by winding actuator shaft gaskets from string soaked in an Apiezon grease.

MDC stainless steel vacuum gate valves incorporate patented C-Loc® and Uni-Loc™ gate valve locking mechanisms. No contact is made between a valve's body and the locking mechanism, a feature which markedly decreases vibration and in sures smooth valve operation.

MDC gate valves require about half the number of moving parts found in comparable competitor valves. This reduction in moving components minimizes wear and particulate generation which in turn provides valves of superior performance and reliability. The valves' low outgassing characteristics can be attributed to a fusion welded 300 series stainless steel body, welded AM-350 stainless steel nesting bellows as well as small cross-section O-rings and the elimination of blind internal cavities.

MDC circular gate valves are offered in various sizes ranging from 0.625" to 12" port diameters. Standard port mounts include:

  • Del-Seal™ CF metal seal flanges, which are recommended for ultrahigh vacuum service
  • ISO Kwik-Flange™ and ISO Large-Flange™ fast make and break elastomer sealed flanges, ideal for high-vacuum applications requiring frequent assembly and disassembly
  • ANSI / ASA elastomer seal port flanges for use in high-vacuum applications where ANSI standards are specified

Gate valve actuation is available in both manual and electropneumatic configurations.

Custom designed valves are available on request.

  • Ultra-high vacuum (UHV) series
  • Circular apertures ports
  • Del-Seal CF ConFlat port flanges
  • Stainless steel construction
  • Electropneumatic actuators for pneumatic operation
  • Patented C-Loc® and Uni-Loc™ locking mechanism
  • 120VAC air control solenoid valve, with 24VDC or 240VAC options available
  • OFE copper metal bonnet seals
  • Welded bellows actuator seal
  • TIG-welded internal body joints
  • Electropolished interior and exterior surfaces
  • Dry film lubricated bearings

Port Size

Port Flange


Flange Thread


Body Carriage & Gate            


Air Cylinder                              



Bonnet Seal UHV                    



Electropneumatic Actuator

Air Pressure                             

Air Control Valve                     

Solenoid Power                       

Power Loss                             

Position Indicators                   



Leak Test

Temperature Range




Reference Number                            

6.00" (6.00 inches) | 152.4mm

Del-Seal CF ConFlat (CF) Flange




300 series stainless steel (SS)

AM-350 SS

Teflon® coated aluminum

300 series ss, silver plated


OFE copper elastomer

Fluorocarbon-based fluoroelastomer (FKM / FPM) or optional Kalrez® 4079 elastomer

Fluorocarbon-based fluoroelastomer (FKM / FPM) elastomer


70 to 100 psig

410 series Humphrey solenoid valve

120VAC, 50 / 60Hz, 4W

Valve closes

Mechanical, vernier adjustable, hinged-roller type micro switches suitable for 5A, 120 / 240VAC


1x10-11 Torr

2x10-10 cc/sec of He

Bakeability under vacuum in open-closed positions, with the following bonnet-gate seal combinations

Series    Open   Closed    Bonnet    Gate

UHV       250¬∞     200¬∞C     Copper   Kalrez®

37 pounds / 16.8 kg


  • Superior sealing performance for minimal surface erosion
  • Bidirectional / dual direction for non-restricted flow
  • Simple body, compact structure for easier operation
  • Energy-efficient for reduced total ownership cost
  • Wide application range
  • With air control solenoid valve standard option, reduced particulates during pump down and reduced stress on high vacuum pump
  • Ultra-high vacuum (UHV)
  • Aerospace
  • Industrial
  • Life sciences / bio-medical
  • Research
  • Semiconductor

Hardware Name

Thread Length

For Use With Flange Type

Quantity / Package

Reference Number

Part Number (SKU)

12pt Head Bolt Set

.312-24 UNF x 1-3/4" /

5/16"-24 UNF x 1-3/4"

Del-Seal CF / ConFlat (CF) 25 BA-600-12-SP 190059
  • Modular electromechanical position indicators
  • Air control solenoid valves for 240VAC and 24VDC service
  • Valve body roughing ports
  • High-temperature 250¬∞C Kalrez elastomer gate seal

When ordering standard gate valve options, please select from the part number (SKU) extensions below:

Option Name


Valve Size 

Roughing Port Size

Flange Size / Type

Standard Options Part Number (SKU) Extension

Mechanical Position Indicator MDC circular C-Loc® gate valves can be fitted with optional high precision, modular mechanical position indicators (MPI). This new MPI system consists of two single pole double throw micro switches fitted with integral hinged lever and roller actuators. Each micro switch is wired in a normally open position. Normally closed switches are available on request, and easily modified by reversing standard factory wiring. Precise positioning of each micro switch is possible by a patented vernier mechanism found only on MDC gate valves. MPI connections are made via industry standard seven pin circular threaded connectors supplied with mating female cable connectors. All pneumatic valves include solenoids pre-wired through MPI connector box.

Available for all valve sizes

N / A Available for all flange sizes / types -01

Air Control Solenoid Valve


Optional 24VDC solenoid valves are fitted with DIN type connectors that conform to international standards. DIN connectors provide simplicity, convenience and fast, easy electrical installation. Solenoid valves come standard with push button / spring return manual override. Manual override is located at top of solenoid and identified by a prominent red push button. Solenoid valves are designed for use with compressed air from 0 to 100psig. Air should be clean and uncontaminated. When in doubt, install a filter with filtering capacity of 40 microns. Periodically remove and clean or replace filter element. All solenoid electrical leads are pre-wired to MPI box connector.

Caution: Check voltage label on solenoid before connecting power. Do not separate coil portion (black) from body (aluminum).

Available for all valve sizes
N / A

Available for all flange sizes / types

Air Control Solenoid Valve


Optional 240VAC solenoid valves are fitted with DIN type connectors that conform to international standards.

Refer to option -03 description above.

Available for all valve sizes

N / A
Available for all flange sizes / types
Roughing Port

A roughing port provides a path to a vacuum chamber through the gate valve body. With the gate closed, the valve body and chamber may be evacuated by a vacuum roughing pump.

With the exception of the 0.625 inch / 0.625" gate valve, all valves can be fitted with roughing ports. Valves with Del-Seal CF ConFlat (CF) and ANSI / ASA port flanges are supplied with Del-Seal CF ConFlat (CF) roughing port flanges. All Del-Seal CF ConFlat (CF) roughing ports are tapped. Valves with metric port flanges have Del-Seal CF ConFlat (CF) roughing port flanges with metric tapped holes. Gate valves fitted with ISO Kwik (KF) and ISO Large (LF) port flanges are supplied with ISO KF roughing port flanges. Roughing ports will be installed on the side opposite the gate seal (the carriage side of the valve). Although the location of the roughing port does not affect its function, the positioning of the gate is important.

1.5" to 3.0" valves 0.75" port

1.33CF Del-Seal CF / ConFlat (CF)


ISO-NW16 Kwik-Flange (KF)

Roughing Port See option -04 description above 4.0" to 8.0" valves 1.5" port

2.75CF Del-Seal /
2.75" ConFlat Flange (CF)


ISO-NW40 Kwik-Flange (KF)

Roughing Port See option -04 description above 10.0" and 12.0" valves 2.0" port

3.37CF Del-Seal CF /
3.37" ConFlat Flange (CF)


ISO-NW50 Kwik-Flange (KF)

High Temperature Gate Seal

UHV series valves, which have metal sealed bonnet flanges, can be ordered with the high temperature Kalrez® compound 4079 gate seal gasket option. Kalrez compound 4079 O-rings are suitable for vacuum bakeout to 250¬∞C (with gate in an open position). Kalrez compound 4079 offers excellent chemical resistance and good mechanical properties. When compared to Fluorocarbon-based fluoroelastomer (FKM / FPM) elastomers, Kalrez®has lower outgassing characteristics for any given temperature from ambient to 250¬∞C. Other special seal materials may be discussed with the MDC technical sales engineers.

Available for all valve sizes

N / A

Available for all valve sizes flange sizes / types


Option Combo





Mechanical Position Indicator: -01


Air Control Solenoid Valve, 24VDC: -03

Available for all valve sizes

N / A

flange sizes / types


Option Combo






Mechanical Position Indicator: -01


Air Control Solenoid Valve, 24VDC: -03


Roughing Port, 4.0" to 8.0" valves: -05

4.0" to 8.0" valves

1.5" port

2.75CF Del-Seal /
2.75" ConFlat Flange (CF)


ISO-NW40 Kwik-Flange (KF)



More Information


Weight (lb) 37.00
Flange Thread Type UNF
Material 300SS Stainless Steel
Port Size 6.00" (6.00 inches) | 152.4mm
Reference Number GV-6000M-P
Vacuum Range 1x10-11 Torr
Vacuum Series Ultra High Vacuum (UHV)
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