Under certain conditions, manually operated valves can be difficult to open and close. The valve may stick, freeze, or be used so rarely that its internal parts become fused. In addition, large valves are often difficult to operate when using a standard chain wheel. In answer to these problems, Roto Hammer® offers the M Series Hammer Blow Impact Actuator. The Hammer Blow mimics the motion of a hammer striking an anvil and delivers a quick, measured blow that will free up a sticky valve without damaging its internal or external parts.

  • Ideal for overhead valves that tend to stick or are otherwise difficult to operate
  • Available in chain model (for operation above ground level) or hand wheel model (for ground level operation)
  • Either style (chain or hand model) may be ordered for Clamp-On or Direct-Mount installation
  • Direct-mount models are furnished with an adapter plate that replaces the existing hand wheel. This plate can be supplied blank or machined to fit the valve. If fitted, dimensional information is required.

When ordering, provide diameter of existing hand wheel, dimensional information (for direct mount option only) and length of chain required.


Chain wheel MUST be installed properly for safe operation. Follow ALL Installation instructions carefully.
NEVER install an M-Series Impact Operation on ANY make, model or type of GEAR OPERATED valve.
To eliminate any possibility of the valve handwheel retaining nut backing off the stem, IT MUST HAVE A SET SCREW IN PLACE.
EVERY Impact Operator must be scheduled for REGULAR, PERIODIC inspection and maintenance.
Roto Hammer STRONGLY RECOMMENDS that EVERY overhead Impact Operator be fitted with a Roto Hammer Retaining Cable (available from your local distributor or from Roto Hammer Industries).
Set screws and other threaded fasteners MUST be secure and tight.