Operation; Work On The Opened Valve - Mankenberg UV 5.1 ATEX H2 Betriebsanleitung

Supplement to the Operating Instructions for
Back pressure regulators UV 5.1 ATEX H2
The adjusting screw is secured against dislocation. This securing device must be checked regularly.

Operation

In order to avoid different ignition sources in the event of the valve or its components getting broken during
operation, strictly adhere to the specified maintenance intervals. Use only original spare parts. Only personnel
who has been specifically trained for the operation and maintenance and receives regular in-service training
may work on the product.
Perform maintenance work regularly according to the maintenance schedule. Particularly give attention to
corrosion and wear and tear of components because these may lead to the creation of additional ignition
sources.
The specification of a minimum flow rate according to the intended use must be strictly observed. To avoid the
recurrent quick opening and closing („rattling") of the valve. Such unstable operation condition may cause
potential ignition sources to become active.
Quick opening and closing of the valve caused by influencing the operation parameters, for ex. by using a ball
valve or final consumers, lead to shocks and increased wear within the valve and may cause potential ignition
sources to become active.
Explosive decompression can damage the elastomers. Leakage can be the result. After rapid pressure drops,
large pressure differences or emergency shutdowns, check the valve for function and tightness.
In shock waves and adiabatic compression, temperatures can be so high that explosive atmospheres can be
ignited. The temperature increase depends essentially on the pressure ratio or the pressure change over time,
but not on the pressure difference.
An exothermal reaction (ignition source) may occur if an inappropriate lubricant gets into contact with the
operating medium. Its suitability must be verified by the Operator. If necessary, check with the Manufacturer for
a suitable lubricant.
The valve was designed to be technically tight. For continuous technical tightness the Operator must take
organisational measures such as regular maintenance and monitoring. The valve must be checked for tightness
during the first start-up, after longer shutdowns, modifications and repair or conversion work. In addition, valves
that are technically tight must be regularly checked for tightness in accordance with a test plan, for ex. with a
foaming agent in order to avoid leakage (zone entrainment, zone expansion). Measuring points to be checked
are for ex. interfaces to the plant, the connection between body / bonnet.
If the tightness test has not been passed, the procedure described for maintenance or troubleshooting (help in
case of a malfunction) must be followed.
A soft-seated cone can be an ATEX protective measure, in case of damage this function cannot be fulfilled.
Check valve regularly for increased seat leakage (according to data sheet), replace maintenance kit parts, if
necessary.

Work on the opened valve

The following measures have a preventive character. They prevent abrasion and that potential ignition sources
become effective.
Mounting procedures must not be performed in explosive atmospheres in order to prevent mechanically
generated sparks originating from installation tools or falling components.
Comply with the indicated tightening torques for screw connections in order not to jeopardize the tightness or
the functionality and to exclude possible ignition sources.
Use the specified threadlockers to prevent loss of the screw connection.
Adhesive used for screw retention must withstand 20 K more than TS max of the nameplate, observe adhesion
position in the drawing!
Tighten the screws manually in order not to overstress them.
Lubricate the specified points with the specified suitable lubricant in accordance with the Maintenance
Instructions.
Check the movable parts for ease of movement.
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UV 5.1 ATEX H2-4.X.22.5 Issue 21.12.2022 www.mankenberg.com