Monday, October 22, 2012

Duo disc wafer Check Valve-Installation & Maintenance Manual








Installation & Maintenance Manual










1INTRODUCTION ...................................................................................................... ....... .. 2
2 PURPOSES.................................................................................................................. ... 2
3 DESIGN FEATURES........................................................................................................ . 2
4 STRUCTURE AND PART LIST......................................................................................  .... 2
5 INSTALLATION.................................................................................................................. 3



1 INTRODUCTION
The design of this type of check valve has good structures and appearance.  The discs open under the flow pressure with direction from inlet port to outlet port. When the inlet pressure is lower than outlet pressure, the discs close automatically due to differential pressure and weight of the discs as a result of preventing backflow. The valve is designed according to API 594 with face to face as per ASME B16.10 and the pipeline flange to ASME B16.5, the pressure test of this type valve is according to API 598. This type of valve is widely used in industries like petroleum, water, natural gas etc. as well as power plant, metallurgy and textile industries.

2 PURPOSES
This type of valve is widely used in petrochemical ad general industrial pipelines for preventing pumps and other power driven machine from reversing, as well as releasing mediums in the machines. 

3 DESIGN FEATURES
3.1 Discs can automatically close with the effects of springs, fast in closing as to keep the medium from backflowing.
3.2 The valve can be installed horizontally and it is light so that supporting seat is not necessarily required.
3.3 Discs can fully open with a little differential pressure, fast speed and good sealing performance.
3.4 Flow coefficient is 2.6 to 0.7, it becomes smaller as the valve size is larger.
3.5 Short face to face, small volume and light weight saves material, therefore reduces the cost.
3.6 The valve is one-piece type, simple and compact with low water hammer effect, the life span of this valve is long and it is reliable.

4 STRUCTURE AND PART LIST


5 INSTALLATION
5.1 Before installation, check the body cavity if it is clean and no dirt of other corrosive residue, remove dirt and clean the valve, repair the defects which are caused during the transportation.
5.2 When installing the valve, verify the operating requirements are in accordance with that marked on body and nameplate. Check if the model of the valve, flange size and face to face length is suitable for the application pressure and temperature. 
5.3 Dual plate check valve is normally installed horizontally in vertical or horizontal pipelines.                            5.4 Pay special attention to the flow direction when installing the valve, the flow direction shall be the same as the arrow marked on valve body, otherwise the valve will cut the flow required. 
5.5 When the check valve is closing, the water hammer pressure will emerge. It will be too serious to cause damage to the valve , pipeline or equipment, specially for big size or high pressure pipelines. Users shall pay highly attention to valve selections



                                                Sangong Flow Control Co., Limited
                                                                                                         www.sangongvalve.com

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