Wednesday, March 26, 2014

Need a Valve for Abrasive or Corrosive Slurries?

Need a knife gate valve thats great for corrosive, abrasive or slurry service? Check out a urethane lined knife gate.

Urethane Lined Knife Gate Valves are designed for on-off and throttling applications of abrasive slurry and dry abrasive materials. These valves are ideally suited for applications in mining, chemical and food industries. They are bi-directional and have tight shut-off and can be used for on/off service or for control.

Urethane Lined Knife Gate Valves are available in sizes 2-48" (50-1200mm) with temperature ratings from -40 to 180°F (-40 to 82°C) as standard, with a variety of urethane compounds available on application.

A one-piece, cast-in-place liner that provides bi-directional, drip-tight shutoff to either 150 or 250 psi (1030 or 1720 kPa) CWP are available. All wetted surfaces of the ductile iron body are lined with urethane. These valves are good for dead-end service.

Tuesday, March 4, 2014

What is a Declutchable Manual Override Gear Operator?

Declutchable Manual Gear Operator
Typical Declutchable
Manual Gear Operator
Declutchable manual gear overrides enable users to manually position their valves to a desired position safely and easily. Gear overrides typically enable 90 degree rotation in either direction and are designed to manually override double acting or spring return actuators.

Designs vary, but most include a self-locking, declutchable worm gear which is designed to provide a secure engagement keeping the valve firmly in position. Declutchable manual gear overrides are usually designed to be “sandwiched” between a pneumatic actuator and quarter-turn valve, allowing the operator to manually operate a pneumatic actuator in case of emergency power or air loss.

Construction normally protects the gears in a completely enclosed, weatherproof and permanently lubricated enclosure. The operation is done via some type of hand wheel. A wide variety of torque outputs are available.

When selecting a declutchable manual gear override consideration must be given to valve torque requirements, weight, size, mounting, operating environment, and criticality of application. An experienced valve application engineer should be consulted prior to selection.