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1.The pipelines before and after the valve are ready, the pipelines should be coaxial, and the sealing surfaces of the two flanges of the flange connection valve should be parallel. The threaded connection valve thread should be intact. The thread standard should match the valve. The pipeline should be able to bear the weight of the valve, especially when the valve is installed lying flat, proper support should be made to the valve to prevent damage to the valve parts.

2.Purge the pipes before and after the valve to remove oil stains, welding slag and other debris in the pipes.

3.Check the mark of the valve to find out that the valve is intact. Fully open and close the valve several times to confirm that it is working properly

4.Remove the protective parts on the connecting ports at both ends of the valve.

5.Check whether there is any foreign matter in the flow passage in the valve. Even if there are only small foreign matter between the valve plate and the sealing surface, it may damage the sealing surface of the valve seat.

1 It is necessary to verify that the upstream and downstream pipelines of the valve have been relieved of pressure before disassembling.

2 Care must be taken to prevent damage to the sealing surface of parts, especially non-metal parts, when disassembling and reassembling.

3 The bolts on the flange must be tightened symmetrically, gradually and evenly during assembly.

4 Metal chips, fibers, grease (except those specified for use), dust, other impurities, foreign objects, etc., should not be allowed to contaminate, adhere or stay on the surface of the parts or enter the cavity during assembly.

1 The valve is forbidden to be transported by hanging on the handwheel with a hook

2 Before the valve is used, both ends of the flow channel must be plugged with valve sleeves to prevent dust impurities from entering, and there must be plug sleeves to protect the sealing surface. Keep the valve dry and ventilated. When the valve is not used for a long time, the inner cavity of the valve should be cleaned. Clean, additionally coated with anti-rust oil to prevent rust.

3 Before the valve is installed, it is necessary to check whether there is any impurities in the valve cavity, and check whether the valve is open or closed.

4 The valve must be installed in the pipeline in a horizontal state, and must not be suspended, inclined, etc., and a bracket must be provided in the suspended position.

5 Each time the valve is opened and closed, the valve position indicator must be in the same position as described above.

6 When the valve needs maintenance in the pipeline, the valve should be in a half-open and half-closed state, and then withdraw for maintenance

7 During the use of the valve, check the tightness of the bolts and nuts, and stop when necessary.

 

1 The detailed valve and pipe flange installation method are as follows

2 The position of the valve installation pipe is as shown in the figure below (the valve can be installed in various positions, but we recommend using it in the most suitable position):

3 The valve can only be installed in one direction. The direction of the sealing ring is consistent with the flow direction of the medium. The user must confirm the flow direction of the medium and install the valve in the direction of the arrow on the valve body.

4 After the flanged valve is welded and installed on the pipe flange, do not install the valve immediately. The pipe work can only be carried out after normal temperature. It is absolutely forbidden to weld the pipe after the valve is installed on the flange;

5 When installing the valve, you should consider the convenience of operation, and install the valve in an easy-to-operate place as much as possible;

6 Tighten the bolts on the flange according to the above installation method. The pipe bolts should be tightened diagonally. Be careful not to tighten unilaterally. Unilateral tightening may cause leakage;

Note! It is advisable to use proper force when screwing the fastener bolts to achieve a complete seal between the flange and the valve.

1 The operating pressure shall not exceed the pressure in the product performance specification table and the operating temperature of the product.

2 When the valve is installed horizontally, the valve should be supported accordingly, especially to prevent the large-diameter valve driver from damaging the valve due to gravity.

3 When cleaning the pipeline, the valve should be in a fully open state.

4 Valves with cleaning pipes should be cleaned regularly (preferably once a week), and the specific cycle depends on the specific working conditions;

5 Take measures to prevent long-term violent vibration of the valve on the pipeline to avoid fatigue failure and leakage of the valve.

6 The valve must not replace the packing under pressure, and the upper sealing structure is not a reason for the user to replace the packing under pressure.

7 The design of this valve has not carried out life calculation, test and fatigue strength check, and the user must regularly check and replace it during use.

8 The design of this valve does not consider the seismic load, and the manufacturer is not responsible for the consequences caused by this.

9 The valve must be protected when installed in the open air.

10 During the use of the valve, the stem, stem nut and bearing should be lubricated once a week to ensure that the valve can be opened and closed flexibly.

The customer should provide the valve type, size, pressure, temperature, and description, etc.

In the case that the customer does not provide the structural length, our company installs API 6D as the standard

In the case that the customer does not provide the flange standard, our company installs it with ANSI B 16.5a as the standard

Please provide standard number and detailed information

Note: For more than two times of switching (excluding the second time), sealing grease must be added to make up for the natural leakage of sealing grease due to over-frequency switching, so as to ensure the dosage of sealing grease in the valve body. If you need to repeat the switch pressure test several times, follow the above requirements and so on.

DASTON 7903 is formulated from synthetic fluids, thickened by organic clay thickener.

Features & Benefits

●Excellent adhesion and sealing function;

●Good properties of pressuree-resistance, vibration-resistance, insolubilization, non-separation, non-solidifying;

●Resistance to gasoline, kerosene, lubricants, water, LPG etc.;

●Excellent thermo-stability and chemical stability.

Applications

●Suitable for static sealing on equipment, piping and valves which contacts with gasoline, kerosene, lubricants, water, LPG and other media, and also suitable for sealing and lubricating on sealing surface with slowly sliding and rotating;

●Especially suitable for lubrication and sealing of the oil and gas pipeline, valves etc

Process of opening and closing of the valve. When open the valve, firstly turn the handwheel to make the plug lifted and separated with the sealed surface, then turn the handle by 90 degree to connect the channel of plug with the channel of valve body. So that the valve is opened. When close the valve, firstly turn the handle by 90 degree to make the channel of plug vertical to the channel of the valve body, then the handwheel to descend the plug, so that the valve is closed.

Before delivery LIIXN made test for all the valves,and why it also have leakage?

We presume that:

1. When the valve is make pressure test, there will be force to cause the packing to expand, and after the test, the external force is lost, which may cause the bolt to be a little loose

2. The valve needs to be ultrasonically cleaned before leaving the factory, so that the dirt and oil on the surface of the valve can be removed, but when it is cleaned by ultrasonically, it will vibrate and cause the bolts to become loose.

Our metal seated Knife Gate Valve is made as per the specification of MSS SP-81.As we see, the article 10.2 of this standard specified the leakage rate of this valve,that means the valve’s seal leakage is allowable.

Through all the international manufacture designs of metal seated knife gate valve,disc seal need very big pressure ratio,but actually the seal can only offer little pressure ratio because the structure design,it too hard to fulfill,so caused seal leakage.

If the medium is dry ash,paper slurry,particle calcium carbide etc. self-seal flow.From the view of physics,the water molecules’ diameter is far smaller than dry ash and other composition of the flow.It’s more easier to across the micro tunnel of seal face,cause leakage.But the self-seal medium will jam the micro leakage tunnel automaticly under the pressure when the valve is closed,and this can reach the leakage rate of the national standard,and fulfill clients’ application.

So,we do not do seal tests,and shell hydraulic test only.

LIXIN DBB Plug Valve is designed, manufactured,tested according to API 6D, it has DBB function of API 6D . Mechanical clamping combined with elastic sealing can achieve strictly sealing. Fully closed disc and seat can form second seal and fire safe. The external safety relief valve relief at 0.2Mpa pressure, prevent abnormal pressure cavity boost.

DBB Plug Valves meet the requirement ofANSI 150 to ANSI 900 (PN20 to PN150) standards. Body can be carbon steel, stainless steel and alloy steel. Size range 2 “to 36” (DN50 to DN900).

DBB Plug Valves have API 6D short series with rectangular hole channel, necking rectangular hole channel and the hole full bore valve

DBB plug suitable for the place need to be more tightly sealed, such as fuel storage and distribution, natural gas, liquefied petroleum gas, oil and other pipeline, used as a cut seal.

Soft rubber seal on the slip of DBB valve wear and tear,the slip can be changed according to nameplate or serial number code.

DBB plug, the following can be referred to as “valve”.

Valve rated pressure: The valve pressure – temperature rating shown by Class to determine the appropriate  rating  level  pressure  according  to  ASME  B16.34  Material  Group  table.  The  valve pressure – temperature rating shown by PN determine the appropriate rating level pressure. according to EN 1092-1 table.