Contact Us
AMOT Offices

Customer Service - Americas
Tel: +1 888 566 2668

Customer Service - Europe, Middle East and Africa
Tel: +44 1284 715739

Customer Service - Asia Pacific
Tel: +86 21 5910 4052

Customer Service - Germany
Tel: +49 40 8537 1298

Customer Service - India
Tel: +91 77100 26802

Send us a Message

International Distributors Find a Local Distributor

4109 Vibro-Guard Vibration Valve

SKU 4109

AMOT Model 4109 Vibro-Guard Valve is a 2-way acceleration sensing valve with optional electric microswitch. It is closed under normal conditions and trips open to vent when vibration or shock exceeds the set level. This venting action, when used in a pneumatic safety control system, can be used to sound a pneumatic alarm or shut down malfunctioning equipment, or both. Failing bearings, broken blades, cracked, broken or bent shafts, misfiring, and accumulated deposits are a few of the items which the Vibro-Guard can detect.

The unit is available with an optional microswitch for applications where an electrical signal is desired. The valve may be reset manually or by means of a pneumatic cylinder in the cover. The pneumatic reset feature is also used as a starting or time-delay lockout when desired for machinery which vibrates heavily during start up. Since the standard unit is non-electric, it can be used in hazardous locations without an explosion-proof housing. This unit is weatherproof and corrosion protected for salt spray atmospheres.

The Model 4109 trip point is easily adjusted to the desired level of sensitivity after installation and is highly repeatable once set.

Features and Benefits

  • Anodized (Gulfproofed) finish
  • Pneumatic and electric versions available
  • Reliable repeatability
  • Pneumatic reset/override available
Housing and cover material: Precision cast aluminum black anodized
Internal parts: Aluminum and plated steel
Max. operating temp.: 93°C 200°F
Max. valve inlet pressure: 620 kPa 90 psi
Reset pressure: 207-1724 kPa 30-250 psi
Flow coefficient: Kv = 0.17 Cv = 0.2
Vibration sensing range: horizontal surface - 6G vertical surface - 5G
Switch ratings: 125/250 VAC:
125/250 VAC:
28 VDC:
28 VDC:
1/4 hp
10 amp
3 amp (inductive)
24 amp max. in rush
  • Motors
  • Engines
  • Pumps
  • Compressors
  • Fan Drives
  • Any Moving Equipment

Model 4109 makes use of a pivoted lever assembly with a high strength, potted magnet near the end opposite the pivot. When the unit is reset, the magnet is thrust toward the steel armature imbedded in the base and is held there by magnetic force plus the force of the loading spring until the inertia of the lever assembly exceeds the holding force of the magnet and spring. When this occurs, the lever assembly snaps to the tripped position and remains there until manually or pneumatically reset.