According to the requirements of general liquid ammonia crane pipes, the main thing is that all fittings must not be made of copper materials, and they must be equipped with pull-off valves and shut-off valves.
1. The upper computer and UPS power supply should be included in the procurement documents. The crane tube loading automatic control system adopts the distributed control/centralized management control method, and the system adopts PLC. The PLC reserves the DCS communication interface (MODEBUS protocol, RS485 interface) with the central control room. The upper computer of the system is equipped with two computers, one is the host computer and the other is the standby computer.
2. The control of liquid ammonia filling is carried out in the car loading control room.
3. The necessary related data of the liquid ammonia irrigation area is transmitted to the PLC for monitoring through the MODEBUS protocol and the RS485 interface
4. On-site monitoring video of car liquid ammonia filling is introduced into the control room
5. It is proposed to use truck scales for trade settlement when loading cars. Changing the flowmeter to a vortex flowmeter can reduce purchase costs.
6. When supplying crane pipes, the seller shall ensure that the crane pipes move with the tanker within the normal moving range of the tanker without being affected.
7. Crane tube type: bottom tank type, double tube closed type, manual operation;
, Balancer type: spring cylinder type; there should be a reasonable spring cylinder balance system, the balance system can achieve random balance within the working range, so that the alignment operation is flexible, light and easy to maintain.
9. Connection type with tank truck: both gas and liquid are connected with tank truck by stainless steel quick coupling.
10. The manufacture of crane pipes should be carried out in accordance with the requirements of the HG/T21608 standard. All pressure-bearing main pipelines are welded by argon arc welding, and have undergone strict flaw detection and water pressure test, which fully meets the HG/T 21608 standard.
Crane tube rotary joints require precision machining, large bearing capacity, flexible rotation, sealing rings require superior sealing performance, reliability, strong wear resistance, corrosion resistance, and long service life. The seal ring specifications of the same model crane tube should be the same and can be interchanged. The rotary joint should be subjected to a load test, and the rotary joint should rotate flexibly without leakage and permanent deformation. The specific test method is carried out according to the relevant content of HG/T21608.
12. Fasteners for fixing and connecting crane pipe system should be high-strength bolts.
13. The type and size of the weld groove of the crane pipe should meet the relevant regulations of GB/T985. Non-destructive testing should be carried out in accordance with the requirements of JB4730-2005.
14. The pipeline (including valves, etc.) in contact with liquid ammonia provided by the seller should be made of stainless steel.
