Type T valve specifications
Modular range of wall mounted units with 1 - 5 blades
Screw fix front flanges.
Body material - aluminium for lightness, finished in white or light grey Polyester powder coating.
Blades and internal parts - Grade 304 Stainless steel.
Blades pivot on sealed for life ball bearings.
Operating pressures of 25 Pa, 50 Pa, 55 Pa and 60 Pa.
Accurately pre set to pressure but site adjustable if required.
Can be built up in multiple units using aluminium building in frames.
Available with inlet grilles and weather louvres.
To determine which Type T valve(s) is required for your project it is necessary to assess the building leakage and determine the velocity required across open doors (normally either 2.0 m/s or 0.75 m/s) to enable a theoretical supply volume to be established. The British Standard BS 5588 suggests that 25% be added to this to give an actual supply volume and that the valves be sized to handle the supply volume less door and building leakage other than across the open doors.
The formula given for the leakage calculation is:1000T
0.827 x area of gap in m2 x sq.root of the differential pressure (in Pa).
Type T Flow Capacity Chart
| Valve | No of Blades | Flow in m3/s at given pressure | |||
| 25 Pa | 50Pa | 55Pa | 60Pa | ||
| 200T | 1 | 0.31 | 0.466 | 0.475 | 0.485 |
| 400T | 2 | 0.62 | 0.93 | 0.95 | 0.97 |
| 600T | 3 | 0.93 | 1.40 | 1.43 | 1.455 |
| 800T | 4 | 1.24 | 1.87 | 1.90 | 1.94 |
| 1000T | 5 | 1.24 | 2.33 | 2.375 | 2.245 |
Type T Dimensions
| Valve | A | B | Aperture w x h |
| 200T | 210 | 290 | 640 x 222 |
| 400T | 426 | 526 | 640 x 438 |
| 600T | 642 | 722 | 640 x 654 |
| 800T | 858 | 938 | 640 x 870 |
| 1000T | 1074 | 1154 | 640 x 1086 |
Typical protected escape route pressurisation scheme
