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Dual External Dart Valves

Dual eDart

The Dual eDart – or external (to a vessel) dual Dart valve – is specifically designed for the flotation market.  It has been optimised for slurry flow by having two plugs and seats within the body.  This gives the valve a high rangeability and fine control.  Because the valve is external to the vessel it is well suited to upgrade projects and where safety is a concern, the valve, in conjunction with knife gate valves, may be isolated and easily maintained.

Do you have these issues?

  • Poor level control
  • Valve operating outside of the 40-60% range
  • Excessive wear
  • Spillage
  • Bouncing or vibration of valves
  • Maintenance problems

Then eDART external valves will benefit you.  The dual eDart valve is optimised for fine level control of slurry typically on flotation banks.  There are two plugs and seats in this valve body to improve turndown and by using an intelligent signal splitter, such as the eDART DVC, great control may be achieved.

General Information

Features

  • Body fully customised to plant layout.
  • Either front or side outlet (or both).
  • Cage guided plug on 250mm and larger.
  • Inspection hatch / sampler port.
  • Anti-burping bonnet to help avert air build up within the body.
  • Simple maintenance: All internal wearing parts can be inspected and/or replaced without removing the valve body from the process line.
  • Anti-Rotation Device on the plug.
  • Stroke Indication.

Material of Construction

  • Plug and seat – polyurethane or other appropriate wear resistant material (e.g. UHMWPE or Tungsten Carbide).
  • Bellows seals – to give a non-sliding sealing arrangement.
  • Body – rubber lined phenoline painted mild steel.

Standard Sizes

  • 80 mm to dual 400 mm.

Options

  • eDART dual valve controller.
  • Poppet sampler mounted in body.
  • Flushing valves.
  • Full bore or reduced plug and seat.
  • Custom designs available if standard designs don’t suit application, specifically the cartridge valve, see variation below.
  • Smart (HART, Profibus, Foundation Fieldbus), Electro-Pneumatic (4 – 20 mA), Pneumatic (20 – 100 kPa) Positioner.
  • Bias Spring Fail Closed, Fail Fixed or Double Acting Actuator Options.

Applications

  • Flotation machine level control.
  • Distribution box level control.

Product Variations

Cartridge Dart Valve
This valve is a good example of the possible body customisation available.   It ideally suits an existing plant layout or to reduces the amount of civil construction necessary in a new build.  The valve has a rectangular outlet in the same vertical plane as the rectangular inlet and is orientated horizontally.  It is well suited for upgrades where the space between flotation tanks is severely limited. Often-times, the actuator pedestals are rotated 90 degrees on the bonnet and with the use of the LargeActuators.Com internal feedback actuator, both positioners (and a DVC) may be placed on the side of the walkway.  Where tank splillage is a problem, an awning (strong enough to lift the valve) may be constructed above the valve. When used on the last cell of a bank where there is no step, it allows for upwards flow through the seat and can be used in conjunction with a back pressure pipe which reduces the overall hight of the bank or allows the use of a metallurgical sampler.
Dual dart valve with round outlet
This variation of the dual dart valve has a round outlet in the same vertical plane as the rectangular inlet and points 10° down. It is suited to some plant layouts better than the left or right versions.
dual valve with side outlet
In this configuration the pipe outlet is orientated at 10° down and perpendicular to the rectangular inlet. To determine whether a left or right configuration is required, consider a particle entering the rectangular inlet, the orientation is determined from the perspective of that particle: so either down and left or down and right.