Stafsjö D2G Instrucciones De Instalación Y Servicio página 9

5. If the pipeline is to be cleaned by flushing in order to wash out impurities, the valve must be opened 100 %.
Valves with actuator supplied by Stafsjö are exactly adjusted in the end positions:
This adjustment shall not be changed as long as the valve operates correctly.
Only for Valves with electric actuator:
Ensure that the actuator motor stops by the signal of the limit switch for closed and open position of the
actuator. Exceptional force may damage the valve. The signal of the torque switch may be used for signal
for faulted conditions. For further information, see the actuator instruction.
B6 Installation in an ATEX-classified area
Note:
Additional requirements may be found in the actuator instruction, (if any).
This ATEX instruction is valid along other instructions in this document.
In ATEX-classified zones, in accordance with ATEX Directive 2014/34/EU, only valves with ATEX-
classification and the relevant valve marking shall be installed.
Additional requirements are to be find in Stafsjö's ATEX installation instructions for respective category
Additional to the requirements above make sure that:
• The valve is part of the plants earthed system.
• The user has performed a risk analysis of the pipeline and valve in accordance with the guidelines of ATEX Directive
2014/34/EU.
B7 Pressure testing after installation (if necessary)
Each Valve has been pressure tested before delivery by the manufacturer. For pressure test of the pipe section with a
knife gate valve installed the conditions for the system apply but with the following restrictions:
• The pressure test shall not exceed 1,5 x max. working pressure of the valve body (see valve marking). The gate
shall be open.
• Pressure test with valve in closed position shall not be tested more than 1,1x max. differential pressure in
preferred pressure direction, (see datasheets) in order to prevent overload of the gate.
Immediately at this operation check the stuffing box tightness. In case of leakage:
Tighten the gland nuts evenly crosswise and bit by bit until leakage stop. Do not tighten more than
necessary!
Recommended maximum torque
DN
Nm
Ibf x ft
For the valves HP, HX and other high-pressure versions, observe the additional instruction: "Installation
of high-pressure knife gate valves – tighten the gland or double gland".
DN 50 – DN 80 DN 100 – DN 150
20 25
15 18
DN 200 – DN 300 > DN 350
30 35
22 26
Document: is-VALVE, 21-02-11 issue: 15