OPERATION AND MAINTENANCE MANUAL
12-2016
3
1 TECHNICAL DESCRIPTION
1.1 PRODUCT DESIGNATION AND IDENTIFICATION
The subject of this Operation and Maintenance Manual is:
Type 2902 and 2911 drive-ready flanged cast iron wedge gate valves with soft seals.
- full smooth walled bore design
- wedge (closure) embedded in 100% pure elastomer
- non-rising spindle
- stem head-type seal in valve cover (O-rings)
1.2 USE
The gate valves with soft seals are intended for water supply systems, especially for potable water,
sewage systems, and industrial processing systems. The valves are intended for surface and underground
systems and must be installed in horizontal pipelines.
1.3 TECHNICAL SPECIFICATION
The Type 2902 and 2911 drive-ready flanged cast iron wedge gate valves with soft seals are applied in
transfer of potable water, process water and other liquids as approved by the manufacturer.
- Operating temperature range: +70
°
C max.
- Nominal diameter (dimension) range: DN40 to DN500 [mm]
- Maximum medium flow rate:
- liquid: max. 4 [m/s]
- gas: max. 30 [m/s]
- The driving torque at opening start and closing end is as listed below:
- Valve control mode: the standard version of gate valve has the clockwise closing sense of rotation.
The closing sense of rotation can be opposite on special order.
- The valve connection flange design is acc. to EN 1092-2
with the sizes compliant with the nominal pressure values.
- the connection flanges are manufactured to EN ISO 2285210
- Valve drive coupling type: B3
- Installation length: EN 558-1
series 14 - Type 2911
series 15 - Type 2902
- Nominal pressure ratings (PN):
- 2.5 MPa
2 DESIGN
2.1 DESCRIPTION OF THE VALVE DESIGN
Type 2902 and 2911 drive-ready flanged gate valves with soft seals manufactured by F.A. „JAFAR”S.A.
feature a smooth walled bore, a non-ring spindle, and an o-ring spindle seal installed in a head-type valve cover.
The stem is guided by a bushing in the valve cover neck and a sealing plug. The spindle seal is effected by the
plug sealing assembly, which is a system of o-rings. The gate valve closure is a cast iron wedge completely
coated with rubber and featuring a stem nut located on the wedge lug. The stem is equipped with an interlocking
collar installed by necking. From the bottom the stem collar rests on a seat in the head via a bushing which acts as
a sealed bearing. The plug over the flange is secured against loosening with a wire spring ring. The valve cover to
body joints is made with hex cap screws mounted flush with the valve cover and preserved with a paraffin
compound. The valve cover to body seal is a rubber gasket which also seals the bolt penetration points to prevent
any leaks from their leads. All inner and outer cast-iron surfaces of the valve are epoxy powder coated. The gate
valves from DN350 to DN600 feature a wedge guide system made of plastic inserts.
DN [mm]
40 50 65 80 100
125
150
200
250
300
350
400
450
500
Mmax [Nm]
25
50
100
200
250
280
300
320
