Actuator Service & Maintenance 

Maintenance reason:

After the pneumatic actuator is used for a long time, once the control air circuit is polluted, oil, impurities and dust may enter the actuator, causing damage to the actuator (especially the inner wall of the piston mechanism actuator), so that the upper and lower chambers are sealed. If damaged, the actuator will malfunction and cannot be used normally. At the same time, it is very important to monitor the air source pressure of the actuator daily. If the air source pressure exceeds the standard, it is easy to damage the seal of the actuator and deform the cylinder.  

Monitor the water content of the instrument air. If the water content is high, the oil storage tank should be drained before winter to prevent ice crystals from forming in winter.  

Maintenance content: 

Disassemble the actuator, thoroughly clean its interior, supplement auxiliary hydraulic oil, lubricate the sliding parts such as piston, check the piston sealing ring and the inner wall of the piston cylinder, and replace the damaged parts. Adjust the air supply pressure.  

Valve body repair and maintenance

Maintenance reason: 

During the production process, the pipeline will enter foreign matter and accumulate impurity particles, which can easily damage the valve seat and valve ball.  

After the whole equipment is used for a long time, the stressed parts of the valve body, such as valve stem, guide pin, valve ball fixing pin, etc., will be worn out. It should be inspected regularly to keep abreast of the wear and tear of its various components, make a plan for the purchase and replacement of spare parts in advance, and replace it in time when the wear level of a certain part of the valve reaches a certain limit. Avoid sudden failures in equipment applications that cannot be solved in time and affect production.  

The valve seat is easily damaged when foreign objects and impurity particles enter the pipeline, resulting in internal leakage of the valve. At this time, the valve seat should be replaced in time.  

Maintenance content:

Disassemble the valve body, check the wear of the valve stem, guide pin, valve ball fixing pin and valve seat respectively, evaluate and record the wear condition, propose spare parts procurement and maintenance plan suggestions, and replace damaged spare parts.  

Overhaul and maintenance of air control accessories

Maintenance reason:

After the pneumatic actuator is used for a long time, once the control air circuit is polluted, oil, impurities and dust may enter the actuator, causing damage to the actuator (especially the inner wall of the piston mechanism actuator), so that the upper and lower chambers are sealed. Damaged, the actuator will malfunction and cannot be used normally 

Maintenance content:

Regularly check, clean, lubricate and maintain the accessories of the control air path, replace the filter cup and damaged accessories, install a dust cover for the three-way valve, make a systematic record of the spare parts with short service life, and make a purchase plan.

The necessity of regular inspection and maintenance of valves

Internal and external leakage control:

The quality of valve internal leakage and external leakage control is an important parameter that reflects the quality of the valve. Manufacturers have taken various measures to minimize the internal leakage and external leakage of the valve. The internal leakage of the valve mainly occurs at the valve seat, and the external leakage mainly occurs at the valve stem packing and the valve cover gasket. Therefore, to obtain good sealing performance, we must start from these three places.

 The external and internal leakage of oil and combustible gas, especially hydrogen, will not only pollute the environment, but also easily cause fire or explosion. Especially in the process of hydrocracking in refineries, hydrogen is the lightest element because the molecular weight of hydrogen is only 2, and it is very easy to leak. Its colorless and odorless characteristics make it difficult to detect; its flammable characteristics do not allow leakage. All of the above characteristics require a high-performance and reliable valve to provide a bubble-free leak seal to ensure that it is absolutely leak-free.  

The hydrogen explosion limit (V%) is 4.0%~75.0%, and the ignition temperature is 560 ℃. According to the classification principle of combustible gas fire hazard, hydrogen belongs to Class A fire hazard. The mixture of hydrogen and air can form an explosive mixture, which will explode when exposed to heat or open fire. The gas is lighter than air. When used or stored indoors, the leaked air rises and stays on the roof and is not easy to discharge. When it reaches the lower limit of explosion concentration, it will cause sparks explode. Under high pressure, the explosion range of hydrogen gas is widened and the ignition point is lowered, and the contact of steel with hydrogen under high pressure is prone to hydrogen embrittlement and hydrogen corrosion.

Orbit orbital ball valve maintenance requirements

Routine maintenance can ensure that the equipment is in good condition and prolong its service life; system testing is used as an annual calibration and inspection before the equipment is put into operation to ensure that the equipment is put into use safely.

1. Daily maintenance:

1. Grease maintenance,

1) The lubrication frequency of the valve should be at least once a year;

2) Lubrication is required every time the valve stem is found to be leaking;

3) Valves that operate at least once a day should be lubricated at least four times a year;

4) Valves used in corrosion and other special working conditions, valves that operate more than 10 times a day, should be lubricated at least once every 500 times of opening and closing.

5) Orbit ball valves require the use of high quality Ricky grease.

2. Leakage inspection and disposal, 

1) The leak detection location should include: threaded connections such as the bonnet flange on the ball valve and the valve stem packing port.

2) After the leak point is found, record the leak location and leak amount and deal with it, and add the special packing GP-6 of the orbit factory.

3. Ensure that the control air circuit and accessories are clean, the instrument is in good condition, and the air pressure is kept at the required value of the actuator.

4. Ensure that the valve handwheel operates smoothly.

2. System function test:

1. The functional test of Orbit emergency shutdown valve system should include: remote ESD signal shutdown test, pipeline overpressure shutdown test, pipeline low pressure shutdown test, and actuator on-site forced shutdown test.

2. System test results: It is necessary to ensure that the high/low voltage shutdown point is accurate, the ESD signal responds in a timely manner, and the on-site forced shutdown is effective.

3. Test frequency: In order to ensure the safety and good work of the equipment during the operation period, it is necessary to carry out systematic testing and maintenance on the ESD valve of the gas injection part and the ESD valve of the gas production part before gas injection and gas extraction each year.

3. Spare parts required for maintenance:

1. Spare parts required for maintenance shall be provided by Party B.

2. Party B shall provide the spare parts list and unit price, and divide the spare parts into categories 1, 2 and 3. Category 1 means that it must be used for each maintenance and repair, Category 2 indicates that it is frequently used during maintenance, and Category 3 indicates that it is not frequently used during maintenance. When stocking inventory according to the probability of use, it ensures that spare parts are in place in time for maintenance.

• Seals necessary for valve disassembly and inspection to solve the problem of external leakage: upper bonnet gasket, valve stem sealing ring 

• Common parts for valve maintenance: valve seat (can not be repaired to solve the internal leakage problem), valve stem guide pin (easy to wear parts, affect the valve action) 

•Other spare parts for valve maintenance: ball, stem 

• Actuator Repair Parts: Actuator Seal Kit