Installtion & Commissioning


The valve is supplied for installation and can be installed in the pipeline without additional assembly or manufacturing work. Information on installing and commissioning the valve can be found in the valve Installation and Operation Manual.

1We recommend that the installation and commissioning should be checked by an authorized person using the checklist.
2Follow the safety instructions before installation, Maintenance or Removing the Valve from the Line.
3It must be installed as per the standard practices outlined in the Maintenance and Installation Instructions.
4It must be installed as per the standard practices outlined in the Maintenance and Installation Instructions.
SR.No.Physical Location and Placement : Here are few Tips & recommendations
1The valve must be accessible in all circumstances, with Sufficient space for the actuator, pneumatic connections, and any other components of the final control element.
2There should be proper mechanisms in place to allow for manual proofing, to minimize airflow constraints and potential clogging, pneumatic piping to the actuator should be kept as short and straight as feasible
3The valve should be placed in a low-vibration environment, since long or kinked pneumatic tubing might increase valve closing time.
4If significant vibrations are expected, further care should be taken to protect pneumatic connections, or vibration must be minimized using suitable dampening elements.


WARNING : Risk of malfunction due to incorrect selection or incorrect installation and operating conditions. Only use valves in safety-instrumented systems if the necessary conditions in the system are fulfilled.

Additional Information –

SR.No.Mechanical and Pneumatic Installation
1If the process fluid contains solids that could clog the valve, a strainer must be added.
2Blow Out pipelines to remove Pipe scale, Welding spatter, fine chips, and other foreign material.
3Before installing the valve make sure that pipeline flow is in the same direction as arrow indication on the valve.
4The actuator is placed on the valve and correctly inserted into the pipeline in accordance with the installation and operating instructions. Make Sure, the valve accessories are installed correctly.
5Install the valve in accordance with established piping best practices.
6Use self-centering Gasket for Installation of Valve in Line.
7The Globe control valve’s fail-safe position (stem extends or retracts) is set correctly.
8The Tightening torques (E.g., flanged joints) are measured and monitored.
9The required flow direction is followed. The direction of flow is indicated by the arrow on the valve.
10An Air Filter Regulator should be fitted in Air Line ahead of any instrument on the Valve
1The Valve configuration & Material of Construction were selected to meet specific pressure, temperature, pressure drop and controlled fluid condition. Since the body and trim combinations are limited in their pressure drop and temperature Range
2The materials used in the valves are appropriate for the process medium.
3The entire Globe control valve assembly (valve, actuator, valve accessories with Tubing-Fitting) has been tested for compatibility for the specified application (pressure, temperature).
4Based on the required transit time (Opening and Closing) and thrust, the actuator is properly sized.
*The flow of the process medium is blocked by the strainer for a valve with “actuator stem retracts” fail-safe action.
*Globe Control Valves with “actuator stem retracts “fail-safe action must not be filled with a strainer.
SR.No.Operation & maintenance (O & M))
1The flow through the valve is not obstructed, and the plug stem is not clogged.
2The valve is only utilized in applications that fulfil the size requirements specified during the purchasing process.
3Avoid personal Injury or damage to process system from sudden release of pressure of process fluid.
4Disconnect all operating lines to the actuator that provide air pressure or control signals.
5The End User should inspect the Earthing Facility and Valve Parts on a
regular basis.
6Only fully trained, authorized, and competent operational people do maintenance, and only original components are utilized for spare parts.
regular basis. • Only fully trained,
7Maintenance is performed as described in the section on servicing in the associated valve Installation, Operation and   Maintenance Manual.
8Equipment should be cleaned regular basis.
9Cleaning the Valve Stem on a regular basis will keep dirt and grit out of the Packing.
10Vary air pressure in air lines and fittings to the Actuator as per specification to determine the actual Travel Scale Indication.
11Check for air leaks in all air lines and fittings to the Valve Actuator and Accessories
12Ensure that the combined action of Valve Positioner and Valve provide the desired Valve Stem Movement. Also ensure the required fail-safe position of Valve.
Additional Information :
Contact UNIFLOW’s After-Sales Service Department Concerning Any Work Not Described in Section on Servicing or Maintenance in The Associated Valve Documentation. (


* The operator oversees the proof test interval and the scope of testing. The operator must create a test plan that specifies the proof tests and the time between them. We propose creating a checklist to summarize the proof test criteria. Periodic proof tests must be performed at the interval (or frequency) determined by a SIL verification calculation.

*To maintain the overall SIF’s necessary safety integrity, the proof tests must be conducted more frequently than (or as frequently as) indicated within the SIL verification calculation.

* The results of periodic proof tests and partial valve stroke tests (if any conducted) must be documented and evaluated on a regular basis. 

* Risk of dangerous failure because of malfunction in the event of emergency (valve does not move to the fail-safe position).
* Only use devices in safety-instrumented systems which have passed the proof test according to the test plan drawn up through the operator.

* Malfunction because of a non-observance of the required inspection requirements. To test the fail-safe action properly, the following requirements must be met:

  1. Control Valve and actuator are assembled properly.
  2. Control Valve is installed properly into the plant.

* Regularly check the safety-instrumented function of the entire SIS loop. The test intervals are determined, for example on calculating each single SIS loop in a plant (PFDavg ).

Additional Information :
We recommend performing the proof tests based on a checklist.

Visual inspection to avoid systematic failure
SR.No.To avoid systematic failure, inspect the Control valve regularly. The frequency and the scope of the inspection lie within the operator’s responsibility. Take application-specific influences into account, such as:
1Valve Plug stem obstruction
2Corrosion problems (destruction primarily of metals due to chemical and physical processes)
3Material fatigue and Process medium-induced wear
4Abrasion (material removed by solids contained in the process medium)
5Deposits of a medium size Aging (damage induced by light and heat to organic materials such as plastics and elastomers).
6Chemical attack (organic materials, e.g., plastics or elastomer, which swell, leach out or decompose due to exposure to chemicals.

Record any faults in the valve and inform UNIFLOW of them in writing

SR.No.Safety-Related fail-safe action 
1Apply signal pressure to the actuator to allow the valve to travel all the way to its final position (completely open or closed).
2Deactivate the signal pressure. As a result, the valve must move to its fail-safe position.
3Verify that the valve reaches the required end position within the time limit.
4Verify that the valve reaches the required end position within the time limit.

Safety-Instrumented functions of valve accessories :
* Check the safety-instrumented function of valve accessories. Refer to the associated safety manuals of Valve Positioner, Solenoid valve etc.
* Only perform the work on the valve described in the Instruction, Operation and Maintenance Manual


  1. Fail-safe action impaired due to incorrect repair and Maintenance.
  2. Service and repair work must only be performed by trained competent person.
  3. Use Genuine Parts while Servicing or Repairs Like Body Gaskets, Gland Packing, Diaphragm and Actuator Seals etc.
  4. Do not perform unauthorized alteration in Valve.