Contact/FAQ ダウンロード


Bypass Circuit Unit BU Series

BU Series

Bypass Circuit Unit allows reducing pressurization time for the parts with large volume, which helps reducing the total test time.
It also reduces test time.
Air Leak Testers can control Air operated valve(s) of the Bypass Circuit Unit.
There are Single, Dual and Triple valves. Select an ultimate one depending on the shape and volume of the tested parts.
E/P Regulator Bypass Circuit Units are available for Air Leak Testers

Edge & Function

●Air Leak Tester controls the operation of the Bypass Circuit Unit.

●Circuit is selectable among Single, Dual and Triple depending on the shape and volume of the part to be tested.

●E/P regulator is also available.(Only for Air Leak Testers)

Pneumatic Circuit



Precision regulator specifications Electro-pneumatic regulator specifications
Leak Testers Flow Testers
Component Parts Oil mist separator (Positive pressure)

NOTE : Fittings and Pipes for Wide Valves are not included.

Precision Regulator(Comes with a Pressure gauge) Electro-pneumatic regulator
(Comes with a Pressure gauge)
Electro-pneumatic regulator(Note: Cable is enclosed. Make sure it does not pick up any noise from the power line.)
Relief valve
Connection Diameter Rc1/2 Rc1/2(Rc 1/4 for Vacuum Pressure)
Installation Limit The unit should be installed within 3 m from LS-1881 and 5m from LS-R900/R700.



Bypass Circuit Unit Model Classification

BU – ① 0 ② A – ③④⑤⑥

Regulator 1:  Precision Regulator
2: Electro-Pneumatic (E/P) regulator
Air Leak Tester Specifications 0: For All the Models
(With Precision regulator)
1: For LS-1881 (With E/P Regulator)
2: For LS-R900/R700(With E/P Regulator)
3: For Flow Testers
Wide Valve Specifications 1: Single Fill Valve (WV-1)
2: Dual Fill Valves (WV-2)
3: Triple Fill Valves (WV-3)
Test pressure L: Low Pressure (10 to 100 kPa)
M: Medium Pressure (50 to 500 kPa)
V: Vacuum Pressure (-5 to -100 kPa  E/P regulator range: -5 to -75 kPa)
Exhaust Port K: Exhausts from all the ports
(Available for Dual and Triple)
None: Exhausts from Fill Valve 1
With E/P Regulator
Cable Length
B: 1m D: 5m
C: 3m X: Without Cable

NOTE: D is not applicable for LS-1881

NOTE: E/P regulator is not applicable when Bypass Circuit Ready Option is selected.