Channel Mounted Penstock

Stainless Steel Channel Mounted Penstocks

Waterfront’s range of channel mounted penstocks with associated operating equipment will cater for the most demanding specification and applications.


  • Type: Full frame with direct-on operating gear or open frame with remote operating gear
  • Size Range: Designed to suit project specific size and pressure requirements
  • Pressure: Equal to door depth
  • Materials: Stainless Steel Grade SS304, SS316, Super Duplex, Mild Steel with protective coatings
  • Leakage: All penstocks are manufactured in accordance with BS7775

Selection Considerations

  • Size of gate required?
  • In which direction is the flow to be controlled?
  • Will it force the door on to or away from its sealing face?
  • Mounting considerations –Wall, channel, end wall, side wall, rebate mounted?
  • Method of operation?
  • Differential head in metres under static and opening/closing conditions?


Criteria to be considered are:

  • Off-seating head?
  • On-seating head?
  • On and off –seating head ?

On-seating head – Pressure forcing the door onto the frame.

Off-seating head – Pressure forcing the door away from the frame.

Modulating penstocks for flow control purposes where gates may be frequently repositioned and utilise only a portion of the full stroke, require special consideration and may necessitate……

  • Larger than standard stems
  • Slow operating speeder
  • Continuously rated motors on actuators
  • Special heat absorbing drive shelves

Remote operation

Thrust direct on a frame – Non-rising extension systems. Non rising stems rotate through a gunmetal nut in the penstock door. The screwed portion of the stem at the bottom is probably immersed in the water, effluent etc.

Full frame

Used where thrust reaction is accommodated at the top of the frame.

Rising stems

Are connected to the penstock door and work through a revolving bronze nut located in the operating gear. The screw thread at the top of the stem is generally not immersed and is readily accessible for lubrication.

Open top frame

Used where thrust reaction is accommodated at a point other than the top of the frame.


Penstocks can be supplied with the following accessories:

  • Stem Guides
  • Couplings
  • Stem Adaptor
  • Muff Couplings

Fixing Methods

Any of Waterfront’s standard penstock units can be mounted in a channel.

Channel mounted penstocks are fixed into preformed rebates in the sides and inverts of channels by means of a sand/cement non shrink grout to effect a seal between the rebate and the penstock frame.