Fundamentals of Vacuum Valves

ULVAC's L-shaped vacuum angle valve is manufactured in stainless steel and line-up full range of JIS flange specifications. Open/Close parts are double-acting or single-acting cylinders and manually. Connecting flange types are 4 types, of which size ranges are 16A (5/8inch) to 900A (36inch).

* Dimensions between surfaces for cylinder pressure air apply port size are not compatible with some older models


Table of Contents

  1. Operation Methods and Working Pressure
  2. Cylinder Structure
  3. Feedthrough
  4. Flange
  5. Position Indicator
  6. Solenoid Valve for Operation

Operation Methods and Working Pressure

Category Series

VLP Vacuum angle valve(Double-acting)

VLP-SA Vacuum angle valve(Double-acting/Stainless Steel/O-ring shaft feedthrough)
VLP-SB Vacuum angle valve(Double-acting/Stainless Steel/bellows feedthrough)
VLP-MB Vacuum angle valve(Double-acting/Stainless Steel/UHV)
VLP-U Vacuum angle valve(Double-acting/Steal/O-ring shaft feedthrough)

VLB Vacuum angle valve(Single-acting)

VLB-SA Vacuum angle valve(Single-acting/Stainless Steel/O-ring shaft feedthrough)
VLB-SB Vacuum angle valve(Single-acting/Stainless Steel/bellows feedthrough)
VLH Vacuum angle valve(Manual) VLH-SB Vacuum angle valve(Manual/Stainless Steel/bellows feedthrough)
VLH-MB Vacuum angle valve(Manual/Stainless Steel/UHV)

Series Vacuum level *1 Pressure range abs
[Pa] (torr)
Type Actuation Body material Bakeout temperature
[℃] *2
Allowable pressure difference
VLP-SA V Atm. ~ [1.0E-5] <1.0E-7> (7.5E-8) Angle Double-acting SUS304 150 0.1
VLP-SB HV Atm. ~ [1.0E-6] <1.0E-8> (7.5E-9)
VLP-MB UHV Atm. ~[1.0E-8] <1.0E-10> (7.5E-11) 150(200)
VLP-U V Atm. ~[1.0E-5] <1.0E-7> (7.5E-8) SS400+
Ni plating
60 n/a
VLB-SA Single-acting NC *3 SUS304 150 0.1
VLB-SB HV Atm. ~[1.0E-6] <1.0E-8> (7.5E-9)
VLH-SB Manual
VLH-MB UHV Atm. ~[1.0E-8] <1.0E-10> (7.5E-11) 150(200)

*1 Refer to "Feedthrough" about relationship between vacuum level and feedthrough.
*2 Actuator < 60°C<140F>.
*3 NC = Normally closed (Valve automatically closes when compressed air released).

Cylinder structure

Supported operation systems are three types supporting 0.10MPa;

  • Double Acting Cylinder
  • Single Acting Cylinder
  • Manual


Double-acting: DAdouble acting)


Single-acting (normally closed)



Seal structure types are O-ring-Type or Bellows-Type.


Structural drawing seal-structure-a1.png seal-structure-b1.png seal-structure-c1.png seal-structure-d1.png
Vacuum level/
Working pressure
V ≦10-5Pa V ≦10-5Pa V ≦10-5Pa V ≦10-5Pa
HV ≦10-6Pa HV ≦10-6Pa HV ≦10-6Pa HV ≦10-6Pa
UHV ≦10-8Pa UHV ≦10-8Pa UHV ≦10-8Pa UHV ≦10-8Pa
XHV ≦10-9Pa XHV ≦10-9Pa XHV ≦10-9Pa XHV ≦10-9Pa
Series VLP-SA
  • The feedthrough of VL□-SA is O-ring (FKM)shaft feedthrough, which endures particles.
  • The feedthrough of VLP-U is O-ring (NBR) shaft feedthrough, which endures particles.
  • The feedthrough of VL□-SB is bellows feedthrough, which minimizes outgassing.
  • The Bonnet flange seal of VLP-MB is metal, making it possible to bake out at 200˚C (392F) in the opening position.


The connection flange lineups 4 types and size variety are 16A to 350A manufactured in stainless steel(*1); JIS-VF, JIS-KF, ISO-K, ISO-CF.
The large size of over 500A is manufactured in structure steel(*2).

(*1) O-ring is fluoro rubber: FKM.
(*2) O-ring is nitrile rubber: NBR.


◆ Nominal diameter: A (ISO) mm
◇ Nominal diameter: A (Conventional JIS) mm
● Nominal diameter: B inch

KF...Klein Flansch
Standard: ISO 2861(clamped-type quick-release couplings)
Aka: Quick coupling


Standard: ISO 1609 / JIS B2290 (clamping flange)
Aka: MF flange, LF flange Connection to ISO-F is possible with claw clamp


Standard: JIS B2290 (clamped-type quick-release couplings)
VF: Without O-ring groove
VG: With O-ring groove


CF: Conflict
Standard: ISO 3669-2 (Knife-edge flange)
Aka: Bakable flange, UFC flange, ICF flange


Position indicator(option)


Applicable valve VLP-SA/SB/MB
VLP-U20/U22 VLP-U36
Model W8H D-A54/BT-16(SMC) D-A54/BT-20(SMC)
Position indicator type Lead switch (double wire system, contact switch, cable length 1m (3.28 feet)) Lead switch (double wire system, contact switch, cable length 1m (1.64 feet))
Contact capacity of the position indicator DC24V/5~50mA
Contact capacity of the position indicator Lead switch LED indicator
Valve mounting No mounting with mounting

Recommended solenoid valve for valve operation


  • <*>The old VLP solenoid valve can be used for the new valve.
  • When the solenoid valve for the old VLP-U6, VLP-U14, and VLP-U14R is diverted to the new valve, the operation time may be slightly delayed.
  • Solenoid valves are not available in the new lineup.

Fundamentals of Vacuum Valves


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