Glandular Spade Valve

Glandular valves are designed to provided 100% shut-off gas ducts in continuous process plants. They provide complete isolation of auxiliary equipments, even against pressure excursions, allowing safe access for on-load inspection or maintenance, without having to close down the main process. Unscheduled emergency outages due to auxiliary equipment troubles can therefore be eliminated.

Guaranteede 100% Gas-tightness

FOURESS Glandular valves consist of a steel plate sliding between the proven FOURESS Glandular sealing system. As the blade, in the closed position, extends beyond the seals on all four sides into atmosphere, the valves are 100% gas-tight across the blade, ensuring completely safe isolation of the duct.

Sealing System

Located around the complete inside of the Glandular valve’s frame are one or two sets of flexible metallic looped sealing elements. These seals are constructed of austenitic stainless steel or high nickel alloys, depending on the operating conditions. They are made up in straight sections which, in the unlikely event it should be necessary, can be easily renewed from outside. The seals, whether the valves is open or closed, give a positive metal to metal seal of 30 – 50 mm width and maintain a constant seal between the duct and atmosphere. Because of the flexibility of the sealing elements no moving flanges, or similar devices, are required to facilitate movement of the blade.

Features

Suitability for Dusty Conditions

FOURESS Glandular valves are particularly suitable for dusty conditions because, when open or closed, the area of the blade in contact with the sealing elements is never exposed to the gas-stream. Furthermore the blade on entry has a self-cleaning action, as its thin section slices through any dust build up. Valves are known which have been successfully operated, for over 10 years, in circumstances where the dust level exceeds 1500 mm. 

Isolator Maintenance & Inspection

Seals
As the seals are located on the periphery of the valve frame they can be inspected with the plant on-load. In the unlikely event seals should need replacement, this is done from outside and access is not required to the duct interior.

Operating Gear
The entire valve operating gear is located outside the duct and does not come into contact with the flue gases. The critical components, such as the motor, drive shaft, gear boxes and drive screws can therefore be inspected and serviced at all times. This ensures that, even after long periods of inactivity, the valve will function properly and not , itself , be the cause of a plant outage.
SIZE : FOURESS Glandular valves are available for duct sizes up to 100 m². They are suitable for square , rectangular and with the addition of end plates , circular cross- sections.

GAS CONDITIONS:

FOURESS Glandular valves are suitable for conditions where the normal temperature and differential pressures do not exceed 350°C and - 500 mm WG To + 100 mm WG H₂O . For the higher pressure temperature, special provision can be made in the design.

Standard Design data

BLADE ENTRY : FOURESS Glandular valves are suitable for installation in horizontal , vertical and inclined ducts. The blades can be arranged to enter the duct from above (top entry) , from the side or at an inclined angle.

Sealing efficiency: 100% on CSA without seal air
Duty : ON/OFF

SPADE VALVE: For differentials below 1000 mm H₂O the blade consists of a thin steel plate, larger than the duct cross-sectional area, which is withdrawn completely from the seals into atmosphere, when the valve is open.

ACTUATION: Standard operating speed is 1.25 meters / minute but, by using double start screws or chain drive, speeds up to 10 meters/minute are attainable. The drive system is normally electrically powered and emergency manual drive is provided for operating the valve in the event of power failure.

Single Jack Drive

Spade valves for ducts smaller than 9m² in cross-section can be supplied with a single drive. Thus the blade is moved by means of a single traveling screw jack drive. The screw jack , which has a protective gaiter to prevent dust ingress, is powered by a motor.

Double Screw Drive

Normally the blade is moved by means of a double screw drive. The screws, in protective gaiters to prevent dust ingress, are powered by a motor through two reduction gearboxes. The main drive member is located at either the extremities of the valve, r at approximately duct level.

CONTROL : Limit switches are supplied to control the ‘OPEN’ and ‘CLOSED’ positions of the valve. This facilities interlocking with other electrical controls.

Options

CLEARBORE: Usually the flue frame is provided with internal stiffeners and bracing. The central stiffeners consists of one or more high strength vertical members, edge on, offering minimal resistance to flow. Where required, for example with highly erosive gases, the duct opening can be arranged to be free of any restrictions.

POWER: The drive system is normally electrically powered but can alternatively driven by manually.

FOURESS reserve the right to introduce changes in design or specification should we consider them necessary in the interest of improved performance.

The fields of application for FOURESS Isolators extends to many industries and activities, including :

Fouress Isolators are being used for the isolation of :

Material Specification

Material of Construction