These regulations apply to the installation of gate valves, globe valves, ball valves, butterfly valves, and pressure reducing valves in petrochemical plants. The installation of check valves, safety valves, gate valves, and steam traps is governed by relevant regulations. These regulations do not apply to the installation of valves on underground water supply and drainage pipelines.
Proper Valve Installation is essential for ensuring safety and efficiency.
Proper Valve Installation is essential for ensuring safety and efficiency.
1. Valve Placement Principles
2. Importance of Proper Valve Installation
1.1 Valves should be installed according to the type and quantity indicated on the Piping and Instrumentation Diagram (PID). When the PID specifies the installation location of certain valves, they should be installed according to process requirements.
1.2 Valves should be located in locations that are easily accessible, easy to operate, and maintain. Valves on rows of pipelines should be centrally located, and consideration should be given to providing operating platforms or ladders.
2. Valve Installation Location Requirements
Install shutoff valves on all pipelines that enter or leave the plant’s pipeline corridor and connect to the main pipelines. Group these valves on one side of the pipeline area and provide platforms for operation or maintenance as needed.
Place valves that need frequent use, maintenance, or replacement on the ground, on a platform, or where they can be reached by a ladder. Make sure pneumatic and electric valves are also easy to access.
2.3 Valves that require infrequent operation (used only during startup and shutdown) should also be located where a temporary ladder can be erected if they cannot be operated from the ground.
2.4 The height from the center of the valve handwheel to the operating surface should be between 750 and 1500 mm, with an optimum height of 1200 mm.
Valves that require infrequent operation can be installed at a height of 1500 to 1800 mm. If the installation height cannot be lowered and frequent operation is required, an operating platform or step should be incorporated into the design.
Valves on pipelines and equipment carrying hazardous media must not be installed above head height.
2.5 If the center height of the valve handwheel exceeds 1800mm from the operating surface, a sprocket should be installed. The sprocket should be approximately 800mm from the ground.
A sprocket hook should be provided, with the lower end of the chain attached to a nearby wall or pillar to avoid obstructing access.
For valves in pipe trenches needing ground-level operation, or those below a floor or platform, use an extension rod to position the handwheel about 1200mm from the operating surface.
Avoid using sprockets or extension rods for valves with threaded connections of DN40 or smaller. Minimize use of these accessories where possible.
2.8 The distance between valve handwheels located around the platform and the platform edge should not exceed 450mm.
When the valve stem and handwheel extend above the platform and are less than 2000mm high, they should not hinder the operator’s operation and passage to avoid personal injury.
3. Installation Requirements for Large Valves
3.1 Large valves should be operated using a gear transmission mechanism. The space required for the transmission mechanism should be considered during installation. Generally, valves larger than the following sizes should consider using a gear transmission mechanism.
3.2 Large valves should be equipped with brackets on one or both sides of the valve. These brackets should not be installed on short pipes that need to be removed for maintenance, and consideration should be given to ensuring that the pipe support is not affected when the valve is removed. Generally, the distance between the brackets and the valve flange should be greater than 300mm.
3.3 The installation location for large valves should have space for a crane, or consider installing a sling or beam.
4. Requirements for Valve Installation on Horizontal Pipelines
4.1 Unless otherwise specified by the process, valve handwheels installed on horizontal pipelines must not face downward.
vertically upward; horizontally; vertically upward, tilted 45° to the left or right; vertically downward, tilted 45° to the left or right; not vertically downward.
Especially on pipelines serving hazardous media, the valve handwheel orientation should be determined in the following order:
4.2 For horizontally installed rising-stem valves, the valve stem must not obstruct passage when the valve is open, especially when the valve stem is located at the operator’s head or knees.
5. Other Requirements for Valve Installation
5.1 For valves installed on parallel pipelines, their centerlines should be aligned as closely as possible.
5.11 Valves should not be subjected to external loads to prevent damage from excessive stress.
5.10 Wafer-type valves or butterfly valves must not be directly connected to the flanges of other valves and pipe fittings. A short pipe with flanges at both ends should be inserted in between.
5.9 When installing threaded valves on pipelines, a union must be installed near the valve to facilitate disassembly.
5.8 The valve assembly of the heating furnace’s fire extinguishing steam distribution pipe should be easily accessible, and the distribution pipe should be no less than 7.5 meters from the furnace body.
5.7 Fire water valves, fire steam valves, and other valves within the plant boundary should be dispersed and located in a safe area that is easily accessible to operators in the event of an accident.
The ideal installation height should be 500-1200 mm.
5.6 High-pressure valves have a high actuation force when opened. Brackets must be installed to support the valve and reduce actuation stress.
5.5 Branch shut-off valves in pipe corridors are not frequently operated (only during shutdowns and maintenance). If a permanent ladder is not available, space should be reserved for temporary ladders.
5.4 When branching from a main pipe, the shut-off valve should be located on a horizontal section of the branch pipe near the root of the main pipe to allow fluid to drain completely to both sides of the valve.
5.3 Valves on the bottom piping of equipment such as towers, reactors, and vertical vessels must not be located within skirts unless otherwise specified by the process.
If the valve has a concave flange, the equipment specialist should be consulted to install a convex flange on the corresponding outlet.
5.2 Valves that require connection to equipment outlets due to process requirements should be connected directly to the equipment outlets if the nominal diameter, nominal pressure, and sealing surface type are the same or matching those of the equipment outlet flanges.
When valves are placed adjacent to each other, the net distance between handwheels should be at least 100mm. Valves may also be staggered to reduce pipe spacing.
5.2 Valves that require connection to equipment outlets due to process requirements should be connected directly to the equipment outlets if the nominal diameter, nominal pressure, and sealing surface type are the same or matching those of the equipment outlet flanges. If the valve has a concave flange, the equipment specialist should be consulted to install a convex flange on the corresponding outlet.
5.3 Valves on the bottom piping of equipment such as towers, reactors, and vertical vessels must not be located within skirts unless otherwise specified by the process.
Proper attention to these details is crucial for effective Valve Installation.
5.4 When branching from a main pipe, the shut-off valve should be located on a horizontal section of the branch pipe near the root of the main pipe to allow fluid to drain completely to both sides of the valve.
5.5 Branch shut-off valves in pipe corridors are not frequently operated (only during shutdowns and maintenance). If a permanent ladder is not available, space should be reserved for temporary ladders.
5.6 High-pressure valves have a high actuation force when opened. Brackets must be installed to support the valve and reduce actuation stress. The ideal installation height should be 500-1200 mm.
5.7 Fire water valves, fire steam valves, and other valves within the plant boundary should be dispersed and located in a safe area that is easily accessible to operators in the event of an accident.
5.8 The valve assembly of the heating furnace’s fire extinguishing steam distribution pipe should be easily accessible, and the distribution pipe should be no less than 7.5 meters from the furnace body.
5.9 When installing threaded valves on pipelines, a union must be installed near the valve to facilitate disassembly.
5.10 Wafer-type valves or butterfly valves must not be directly connected to the flanges of other valves and pipe fittings. A short pipe with flanges at both ends should be inserted in between.
5.11 Valves should not be subjected to external loads to prevent damage from excessive stress.
Proper attention to these details is crucial for effective Valve Installation.
