COPYRIGHT©AVK GROUP A/S 2019 - AVK INTERNATIONAL A/S, BIZONVEJ 1, DK-8464 GALTEN - WWW.AVKVALVES.EU
MI GateValvesGas Rev. N June 2019 GB
INSTALLATION AND MAINTENANCE INSTRUCTIONS - ORIGINAL VERSION
AVK GATE VALVES AND SERVICE CONNECTION VALVES FOR GAS
SERIES 02, 03, 06, 36, 38 and 46
1. INTRODUCTION
AVK gate valves are designed for fully open or fully closed service installed in pipelines as isolating valves, and
should not be used as control or regulating valves. Working conditions must be limited by temperature and pres-
sure as stated, normally between -10 and +60 °C, maximum 20 m/s flow velocity and up to 16 bar differential
pressure.
The AVK gate valve is designed with a cast body and bonnet assembled with countersunk bolts of stainless
steel. It is operated with a stem of stainless steel and a wedge of ductile iron fully vulcanized with NBR rubber.
Materials and coating vary according to the application of the valve. Full material specifications are found in the
datasheets. All valves are hydrostatically tested according to EN 13774 for gas applications.
Operation of the gate valve is performed doing an either clockwise to close (CTC) or clockwise to open (CTO)
rotating motion of the stem. When operating the valve stem the wedge moves up- or downwards on the
threaded part of the stem.
Certain variants of the gate valves come with purge point outlets. These outlets are equipped with quarter turn
ball valves fitted with hand lever. The hand lever is pulled upwards to a vertical position to open the valve. The
purge point outlets are fitted with blind flanges, which are pressure tested together with the rest of the valve.
Specific operation conditions may apply for valves equipped with an ISO flange for mounting gearbox or actua-
tor, please refer to the actuator manufacturer’s instructions.
2. PRODUCT LIFE CYCLE
The life of the valve is dependent upon its installation and application.
The valve should be protected from the adverse effects of mechanical shock, loading and excess weight. This
includes forces either applied to it or via the installation process or pipework that the valve is attached to.
Also, consideration should be given to various loadings, which can occur at the same time.
The valve on no account should be tampered with or modified in any way.
If for any reason work is to be carried out on the valve it is wholly the responsibility of the user to ensure the
valve is depressurised and rendered safe prior to any fasteners / fixings being loosened. For replacement
instructions of the stem seal nut, please refer to section 16.
To ensure correct installation of the valve it is essential that the personnel carrying out the installation have cor-
rect training and skills.
As the gate valve is designed for installation directly in the ground, it is designed to be corrosion and mainte-
nance-free throughout the expected life time of the valve. Thus spare parts are not needed and repair of the
valve in case of malfunction is not intended. To maintain full functionality of the valve throughout the expected
life time frequent operation of the valve is recommended. The frequency of operation may vary from once a year
to several times per month.
AVK gate valves are designed to be self cleaning due to the full and straight bore. To get the full benefit of this
AVK recommends to install the valve in upright position or in a 45 degree angle. Upside down installation is not
recommended.
3. CE MARKING AND THE PRESSURE EQUIPMENT DIRECTIVE 2014/68/EU
AVK gate valves for gas are CE marked according to 2014/68/EU.
Valves with a maximum allowable pressure not exceeding 0.5 bar are outside the scope of the directive. Valves
are categorised in relation to the intended fluid contents, the maximum working pressure and the nominal size.
Fluids are classified as Group 1, dangerous substances, Group 2, all other fluids including steam.
Categories are SEP (sound engineering practise) and for ascending levels of hazard, I, II, III or IV. Valves desig-
nated as SEP do not bear the CE mark and do not require a Declaration of Conformity.
Valves classified as category I, II, III or IV carry the CE mark and require a Declaration of Conformity (Note: all
valves up to and including 25mm (1”) having a maximum allowable pressure greater than 0.5 bar are designated
SEP regardless of fluid group).
