Date: 23-Nov-12

Active Device Description Sheet DtEC supplies valve trays with 9 different types of valves. The valve type used is given on the relevant Tray Rating Sheet(s). Brief descriptions are given below:

Fixed Valves FXV Type

Stationary valves pressed up from the tray deck. 4 different sizes (FXV110, FXV60, FXV30 & FXV20) 5 different lifts (clearances). Compared to sieve trays: Higher capacity

Greater turndown Longer lasting in service Mechanically stronger

Particularly suitable for fouling services e.g. HF Alkylation Units. Mini size (FXV30) and Double-Mini size (FXV20) for high capacity trays.

Mobile Legged Valves STD Type

Industry standard circular movable valve. One piece construction with 3 integral legs and guide stops. With dimples to limit contact with the tray deck to 3 points when shut. Used for general applications, except where there are fouling problems. Normal valve thickness used is 1.5mm. Alternate rows of light (1.5 mm) and heavy (2.0 mm) valves to maximise turndown. Very light valves (1.2mm) to minimise dry pressure drop (∆Pdry).

RMV Type Rectangular valves to maximise open area Variable open area to suit vapour flow Variable open area to increase valve density and hence improve tray activity & efficiency Minimised weeping due to perpendicular vapour release & no liquid flow under valves Improved turndown ration compared to round valves Rectangular shape to promote plug flow & hence higher efficiency Large (RMV120) & small (RMV60) size to suit column diameters Wide legs and lack of valve rotation reduce damage due to wear. Very light valves (1.0mm) to minimise ∆Pdry.

Mobile Cage & Disc Valves NCD, LCD and VCD Types

2 piece valves, where a 4 legged hold-down cage attached securely to the tray deck contains a moving valve disc.

Used for general applications like industry standard valves, to give similar performance with the following advantages:

Longer lasting in service, since there is no friction between the valve and tray deck. Less risk of sticking shut or open. The streamlined design of the hold-down cage eliminates

dead zones on the tray deck. Self cleaning i.e. suitable for fouling applications. Better turndown due to less liquid weeping.

NCD Type: Normal valve disc thickness used is 1.5mm.

Alternate rows of light (1.5 mm) and heavy (2.0mm) valve discs to maximise turndown.

LCD Type: Very light discs (1.2 mm) to reduce ∆Pdry. VCD Type: Very light discs (1.2 mm) plus a venturi hole, to minimise ∆Pdry.

RMV120 Valves

FXV30 Valves

FXV20 Valves

VALVE TRAYSDistillation Equipment Company Ltd®