Bottom Blowdown Valve | Gestra Gestra - 1
Bottom Blowdown Valve | Gestra Gestra - 2
Bottom Blowdown Valve | Gestra Gestra - 3
Bottom Blowdown Valve | Gestra Gestra - 4
Bottom Blowdown Valve | Gestra Gestra - 1
Bottom Blowdown Valve | Gestra Gestra - 2
Bottom Blowdown Valve | Gestra Gestra - 3
Bottom Blowdown Valve | Gestra Gestra - 4

Bottom Blowdown Valve | Gestra

GESTRA Bottom Blowdown Valve

The GESTRA bottom blowdown valve is designed for intermittent removal of sludge, salts, and non-metallic solids from the lowest point of steam boilers. Operation is based on rapid opening and closing; an opening time of approximately 2–3 seconds generates a high instantaneous flow and suction at the boiler bottom. Prolonged opening does not significantly improve blowdown efficiency.

Types and Operation

  • PA 46 / PA 47 / PA 48: manual lever operation.
  • MPA 46 / MPA 47 / MPA 48: automatic operation with diaphragm actuator.
  • MPA actuator control medium: compressed air or water.
  • Maximum actuator control pressure: 8 bar.
  • Options: TA timer, limit switches, emergency lever.

Technical Selection Data

Available in PN 40, PN 63, and PN 100 pressure classes, with flanged, socket-weld, and butt-weld connections. For PA/MPA 46 PN 40, sizes DN 20–50 are specified. Indicative pressure/temperature ratings for PN 40: 40 bar at 20°C, 37.1 bar at 100°C, 33.3 bar at 200°C, 27.6 bar at 300°C.

Materials and Sealing

  • Body: 1.0460 / ASTM SA105
  • Seat: hardened 1.4034
  • Cone: hardened 1.4122
  • Stem packing: PTFE yarn
  • MPA actuator diaphragm: EPDM

Installation

Piping between boiler and valve should not exceed 2 m. Downstream piping must be sloped for drainage and to reduce water hammer risk. Flow direction must match the arrow on the valve body.

Compliance

Valve is PED-compliant for group 2 fluids and ATEX classified CE Ex II 2G/D c X for suitable zones, with surface temperature monitored by process medium.

Description

Bottom blowdown valves

Deposits build up very quickly at the bottom of industrial steam boilers.

The way to remove these deposits effectively is by very rapidly opening and closing a valve at the bottom of the boiler, this is called intermittent blowdown.

It is an extremely demanding application which requires a robust and reliable product.

The GESTRA bottom blowdown valve achieves this by opening very quickly, for just 2 seconds, producing a vacuum at the bottom of the boiler.

The resulting suction removes settled sediment, known as sludge, from the bottom of the boiler.

When the valve closes its design ensures tight shut-off with no leakage.

Opening the valve for longer than 2 seconds has no further effect at reducing blowdown and simply wastes water.

Our solutions will help you to...

  • Improve boiler efficiency
  • Save energy
  • Reduce fuel costs
  • Reduce operating costs
  • Maximise system uptime

What are the features?

  • Quick removal of sediment stopping build up
  • Extends life of your boiler
  • Reduces carbon emissions
  • Minimal water and energy losses reducing costs
  • Reduces boiler carry-over for better steam quality and improved plant productivity