Operation and Maintenance Manual

Check Valves

Contents

1. General
2. Essential health & safety requirements of PED
3. Application Scope and Technical Parameters
4. Valve Structure
5. Main Parts and Material
6. Working Principle and Structure Description
7. Valve Transportation
8. Valve Storage
9. Valve Installation
10. Valve Operation and Maintenance
11. Potential Failure and Troubleshooting
12. Quality Warrant
13. Servicing

1. General

Thanks for your selection of YFL check valve. As a type of pressure equipment, valve has potential hazards of pressure resulting from leakage of process fluid. For the safety purpose, user shall read this instruction to know what YFL has already taken into account in our design and manufacture, and what action shall be taken by user according to essential health and safety requirements of European Directive 97/23/EC(PED) .

2. Essential health & safety requirements of PED

2.1 What’s YFL design idea

-Check valve are designed as standard product, no consideration of each specific service condition since its too wide.
-Check valve is designed to BS1868, API 6D, valve has adequate strength according to ASME B16.34 pressure-temperature rating. The check valve was EC-type approved by European Notified Body.
-Valve has different sealing materials in accordance with BS1868, API 6D which are corrosion/wear resistance to certain type of fluid.

2.2 What action user shall taken

2.2.1 General
2.2.1.1 In any occurrence, first ensure personnel safety.
2.2.1.2 Use the valves in accordance with ASME B16.34 pressure-temperature rating.
2.2.1.3 Make sure that the selected valve materials are corrosion/wear resistance to the service fluid.
2.2.1.4 Where the service fluid is flammable/explosive, to limit the working temperature.
2.2.1.5 When performing Repair/maintenance operations, make sure that the valves are always depressurized, vented and drained.
2.2.1.6 When performing Repair/maintenance operations, always use appropriate protection e.g. protective clothing, (oxygen) masks, gloves, etc.
2.2.1.7 When performing Repair/maintenance operations, do not smoke, do not use any portable no-Ex-proof electrical device in the area and do not use open fire without a valid work permit.
2.2.1.8 Valve must periodically checked on:
-Tightness of bolted connection (body/bonnet, flange connection).
-Corrosion/wear damages (crack, pitting, thickness of the valve).

2.2.2 Specifics

Dangerous service fluid as there are: Toxic-, Corrosive-, Flammable-, High- or Low temperature etc. fluid.

3. Application Scope and Technical Parameters

3.1 Application scope

The series valves are widely used in petroleum, chemical, power plant and allied industries for normal operation of pipeline system against converse movement of fluid.

3.1 Technical Parameters:

4. Valve Structure

Please refer to Figure 1 and 2 for valve structure.

Fig 1 . SWING CHECK VALVE STRUCTURE

-Check valve dimensions and weight refer to YFL Flow Control Co., Ltd.

The user or the pipeline system designer must select valve body material and the class according to the working temperature, working pressure, the type of fluid and standard temperature-pressure rating as specified in ASME B16.34. The manufacturer takes only the responsibilities for use the order material and the valve class, no responsibility for incoherence of user selected material and valve class with the working condition.

Table 1   Valve main parts and materials

Table 2 Common used trim material

Table 3  body material suitable for fluid and temperature range

Note: where the process fluid is flammable/explosive, it must limit the working temperature of the pipeline system.

6. Working Principle and Structure Description

6.1 Working principle

This serial is sole direction check valve, when fluid flows at normal direction, the disc opens to fluid pressure; when fluid flows converse, the disc closes to the gravity and converse fluid pressure and cut off the bore.

6.2 Structure description

6.2.1 Flange end or but welding end may be selected as to purchaser optimum.
6.2.2 Valves use a reinforced flexible graphite gasket or spiral wound gasket. ..
6.2.3 The 50 bevel seal is used for the valve and the seal material is applied to API 600 or to the customer requirements.

7. Valve Transportation

7.1 Valves are heavy and metal products, care shall be taken to avoid physical injury during transportation. Before transportation, cord and lift device and transportation tool shall be ready, valve package inspected and broken package repaired. Packaging shall conform to specification requirements.
Valve shall be handled with care, no damage the flange end or butt welding end.

7.2 The paint, nameplate and flange sealing surface shall be protected during transportation, no drag valve on the ground especially with the end sealing surface contacted the ground.

7.3 Don't unpack when the valve is not ready for installation at the construction field. The valve shall be placed at a safety location against whether.

8. Valve Storage

8.1 Valve shall be stored in air and dry room with bore blanked and flange sealing surface protected.

8.2 Long-time-stored valve shall be re-inspected prior to use. Close attention shall be paid against sealing damage when removal of dirties for the cleanness of sealing surface. Of necessary, valve shall be pressure tested once more.

9. Valve Installation

9.1 Carefully check valve identification against valve specifications before installation. The fluid flow direction in pipeline must be consistent with the arrow direction indicated on the body.

9.2 If there is pressure pulse/surge source, the check valve shall be installed far away from the source.

9.3 Check the inside of bore and the sealing surface before installation, any attached dirty shall be removed with clean soft cloth.

9.4 For valve with flange end, user shall select proper bolt, gasket according to the working temperature, working pressure and fluid, equally fasten the bolts and nuts. Bolt shall be with full thread and 8UN serial thread shall be used for bolt over 1 inch in diameter.

9.5 For valve with butt-welding end, user shall perform welding and post welding heat treatment using qualified WPS and welder in accordance with the requirements of ASME B31.3.

10. Valve Operation and Maintenance

10.1 The online valve shall not be knocked, walked on or used as weight support.

10.2 Usually check valves have no heat insulation structure, never touch the surface of valves to prevent burn when the valve has a high/low surface temperature.

10.3 After put into service, valve shall be checked and maintained periodically especially for the condition of sealing surfaces and worn, and the corrosion of body. In case of such situation, valve shall be repaired or replaced. It is suggested that inspection and maintenance of  valve shall be perform every three months provided the fluid is water or oil, every month or to local law provided the fluid is strong corrosive.

10.4 When performing Repair/maintenance operations, user shall use valve gasket, bolt and nut of the same size and material as the original one. Valve gasket may be ordered as spare parts for maintenance and replacement. It is forbidden to open the bonnet or replace the bolt or nut when the valve contains pressure. After replacement of gasket, bolt and nut, valve shall be pressure tested prior to reuse.

10.5 User may repair the valve-sealing surface providing a successful closure test is performed and the sealing is ok.

10.6 Generally valve trim prefers replacement to reparation. It is better to use provided part as replacement. If part produced by valve manufacturer is not available due to emergency, user shall produce the part to YFL's technical documentation . YFL takes no responsibility for loss caused out of part produced from outsourcing.

10.7 It is not recommended for reparation of valve pressure-containing part by user. If the pressure-containing part is used for a long time and consequently defection occurs and affect safety use, user shall replace the valve with a new one.

10.8 Welding repair on valve online is forbidden.

11. Potential Failure and Troubleshooting

12. Quality Warrant

12.1 YFL warrants its valves to the original purchaser for a period of 18 months from and after the date of delivery to the original customer, against defects in material and workmanship under proper and normal use and service and not caused of resulting from improper application or usage, improper installations, improper maintenance and repairs, modifications or alterations.

12.2 Purchaser shall give notice to YFL upon finding of any defect or assuming defect, YFL has privilege to check the facts of the defect.

12.3 YFL sole obligation under this warranty shall be limited to the follows:
—repair of the material or,
—replacement of the parts and materials or,
—refund the purchase price or collect the defected products from the original purchaser.

12.4 YFL is not responsible to claims caused from unexpected natural disaster such as earthquake, typhoon of any kind arising out of the defect.

12.5 The scope and limitation of warranty can be changed through the agreement between YFL and purchaser.

13. Servicing

13.1 Where contractually specified, YFL Flow Control Co., Ltd. may provide field installation and adjustment.

13.2 YFL will trace the quality of sold valve and provide service to customer requirements..