Installation and Maintenance Recommendations For Valve Users

Hard impacts should be avoided during transport, loading and unloading. Using a crane to lift valves larger than 6″, class150-300-600 group valves

For 2″, 3″ and 4″ sized valves, loading is done by holding the handwheel appropriately. Heavier valves or valves without handwheel can be lifted with ropes made of hemp by holding the yoke area on the bonnet flanges.

Storage
If possible, valves should be stored indoors, protected from corrosion and damage. Valve side flanges and open ports are usually covered with plugs, plastic or wooden caps. The internal parts should be dried, lubricated and protected.

Connecting to the Line (Installation)

The valves are shipped with proven sealing tests. The leaktightness of the valves can be maintained by taking measures to prevent foreign debris and dirt from entering the valves during installation, which would cause corrosion of the seats. Care should be taken to ensure that the installation of the valve is carried out in accordance with the operating conditions and the method of operation of the valves (e.g. position of the swing check valve, adherence to the specific flow direction). Usually, the manufacturer will mark the required flow direction. Before installation of the valve, all protective port covers and other applied protection must be removed.

The end connections of the pipes must be adjusted (aligned on the same axis) so that the valve is not subjected to stress after installation. In order to ensure easy use, it is necessary to protect the stem and gland in paint application and to pay attention to the direction marking on the valve.

Flanged Valves

The sealing (RF) surfaces of flanged valves must be in good condition.

Before the valves are connected to the line, the valve flanges must be well aligned with the line flanges. Make sure that there is no axial misalignment before bolting. Bolts should be tightened mutually balanced and evenly for a good sealing.

 

Do not attempt to tighten the valves under pressure at high temperature. Frequent and sudden temperature changes may cause leakage due to elongation of the bolts, but the tightness of the connection will not be affected when normal service conditions return.

Weld End Valves

Welding must be performed by an expert in the field and preferably by a person who has a welder certificate in national standards. The valve and pipe interior must be thoroughly cleaned before welding.

Consult welding reference books for the correct choice of filler material for different body materials.

The weld ends must be well aligned (without axial misalignment) before spot welding. The spotting should be done with the same filler metal that will be used in the weld. The weld ends must be clean and welded with a 1.6 mm gap between the ends.

Welding Heat Treatment
If necessary, preheating should be applied during welding. Consult your welding manual for the necessary pre- and post-heating requirements depending on the material type and wall thickness.

Thermal Insulation
Valf yalıtılırsa, bakım ihtiyacına yönelik olarak glende ulaşılabilir ve salmastra değişiminin yapılabilir olması gözetlenmelidir.

Operating Conditions
Cleaning

Due to the wide variety of chemical cleaners used, it is not possible to define a general cleaning guideline. The cleaning fluid should be selected according to the valve material.

 

The valves must be fully open during cleaning. Afterwards, cleaning should be carried out by swirling in a semi-closed state in order to clean the disc, slide and back ring completely and to remove the dirt in the valve cavities.

Opening – Closing

For manually operated valves, turning the handwheel clockwise closes the valve and vice versa. Do not force the handwheel or lever with a rod or pipe support to close the valve. Gearboxes and actuators are designed to rotate the shaft clockwise (for closing).

Valves with short-circuit (by-pass) regulation should only be opened with the short-circuit valves open to ensure proper balance on both sides of the valve.

Actuator
Before the electric actuator is put into service, it must be rotated at least one turn to ensure proper functioning.

Commissioning

Tightness of all flange connection studs including cover and gland studs should be checked. If leakage is detected, the studs should be tightened evenly in a quarter turn. Continued leakage will cause erosion in the leakage areas.

The tightness of the stud nuts should be checked again after the valves have been exposed to the system temperature (reached the system temperature).

General maintenance
The frequency of valve maintenance is determined by the valve user. This is a matter determined by individual experience with the use and type of valve.

Sealing

Under normal conditions, the sealing materials used in valves are designed to be maintenance-free for a very long period of time when properly preserved in the field or in storage.

For packing replacement, the line pressure must be completely relieved. For this purpose, while the valve is fully open, the relation of the packing housing with the line pressure is completely cut off by turning the handwheel a few turns in the opening direction. Then the gland studs are removed, old packing is removed and replaced with new ones. Then the gland studs are tightened again and the operating conditions are returned.

Lubrication
The moving parts of the valve must be lubricated at certain intervals for trouble-free operation in the field. Lubricants must comply with national standards. Mineral oils should not be used as they age rapidly with temperature increase.

Caution :

Valves in oxygen circuits must be degreased.

Repair

Seat Leakage
The surfaces should be precisely lapped to each other by lapping with suitable tools. If the sealing surfaces are damaged, re-welding, filling, machining and then lapping should be applied. Sealing surfaces with hard surface (stellite filling) are suitable for several lapping and precision lapping.

Packing leakage
The glend studs are retightened or the sealing elements are replaced as described above.

Spare Parts
In order to minimise downtime, it is recommended to have basic spare parts on hand:

Packing set, cover gasket, sealing ring.

Stem and bushing assembly (as a set) 

Sufficient number of studs and nuts