discount 70% in 2018-09-22 to 2018-09-24
price: USD$ 2240.00
freight :USD$7.00,(Postal parcel)
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MZC- II A type differential pressure gauge is mainly used in cryogenic tank, cryogenic liquid tanker and other cryogenic containers liquid gas differential pressure (kPa) display. The components are made up of three units, CYJ-1 double bellows differential pressure gauge, pressure gauge and combined control valve. Features: the combination control valve can replace the upper valve, down valve, balance valve and pressure gauge valve on the storage tank; and the differential pressure gauge and pressure gauge can be disassembled online and replaced, without stopping gas maintenance. The function of each unit is as follows.
Type CYJ-1 double bellows differential pressure gauge
CYJ-1 double bellows differential pressure gauge (kPa) for displaying liquid level in cryogenic vessels. Nominal diameter 152mm, accuracy grade 2.5, range: 0 ~ 15kPa, 0 ~ 20kPa, 0 ~ 25kPa, 0 ~ 30kPa, 0 ~ 50kPa, 0 ~ 75kPa, 0 ~ 100kPa, 0 ~ 125kPa, 0 ~ 150kPa, 0 ~ 200kPa, 0 ~ 250kPa, 0 ~ 300kPa, etc.. It is suitable for liquid level measurement in LO2, LN2, LAr, LNG and LCO2 media. The opening and closing state of the combined control valve can control the display or closing of the CYJ-1 type double bellows differential pressure gauge.
Two. Pressure gauge
The pressure gauge uses YO-100Z type, displays the low temperature vessel vapor phase pressure (MPa), the accuracy class 1.6, the nominal diameter 100 millimeters. Suitable for LO2, LN2, LAr, LNG and LCO2 and other media gas pressure measurement. The opening and closing state of the combined control valve can control the display or closing of the pressure gauge.
Three 、 combination control valve
The combination control valve adopts MZF- II (patent application number: 200620036608). Features: only one rotary handle can replace the upper valve, down valve, balance valve and pressure gauge valve on the original storage tank. The pipeline which is installed with each valve is omitted, the misoperation of the four valves is eliminated, the installation space is reduced, the operation reliability is increased, and the service life of the differential pressure gauge is prolonged. MZF- II type combination control valve has three working states (see Figure 1), as follows:
(1) clockwise open state: clockwise rotation handle to the bottom, the control valve of low pressure and high pressure gas conduction respectively, differential pressure gauge display tank or tank in the liquid level pressure difference (kPa). Pressure gauges show the vapor phase pressure (MPa) of cryogenic vessels.
(2) counter clockwise closed state: counter clockwise rotation handle to the bottom end, low pressure and high pressure gas combination valve input air pressure gauge and air cut-off. At this point, the differential pressure gauge and pressure gauge can be disassembled, maintained and replaced online.
(3) the middle balance state: the rotary handle is between any opening and closing state, and the combination control valve is in balance state. That is to say, the pressure difference between the low pressure and the high pressure gas entering the differential pressure gauge is equal, no pressure difference, the differential pressure meter has no indication value, the pointer is in the zero value range, the differential pressure gauge is in the balanced protection state, but the pressure gauge still has the indication of the gas phase space pressure value.
(1) the installation of MZC- II A differential pressure gauge: the back mounting bracket of differential pressure gauge has 4 through holes with diameter of 10 mm, and the MZC- II A type differential pressure gauge is fixed on the wall panel of cryogenic vessel with 4 M8 screws through the through hole (see Figure five back view).
(2) welding with the pipeline of the storage tank: according to the customer's requirement, the combined differential pressure gauge provides two kinds of stainless steel arc joint connectors with 8 mm in diameter and 6 mm in diameter. Two types of stainless steel gas pipes with welding outer diameter of 8 mm and 6 mm (see Figure six MZF- II type combination control valve connection diagram).
(1) read the differential pressure indication (kPa) of the liquid level:
Calibration: Zero pointer in the storage tank of liquid phase and gas phase pipeline gas under the condition of combined control valve is opened and closed between the intermediate position. The pointer of the differential pressure gauge should be returned to zero range, which indicates that the differential pressure meter works normally.
Read the differential value of the liquid level (kPa): the indication value of the differential pressure meter should be the differential value (kPa) of the static liquid level of the liquid medium in the tank. When the pointer is in the zero position and the liquid level of the storage tank is stable, the combination control valve handle rotates clockwise, and the valve is in the open state, and the differential pressure indication value (kPa) of the liquid level can be read.
(2) the balance function of the combined control valve can be used in the following situations (the middle of the opening and closing of the combination control valve):
Before the reading value of the indicator is checked, whether the pointer is in the zero position or not, the balance state of the combined control valve can be used.
(2) in order to observe the pressure indication of the gas phase space in the storage tank and protect the differential pressure gauge at the same time, the balance function of the combined control valve can be used (at this time the indicator of the differential pressure gauge should be back to zero).
First, when the tank is pressed, second, when the tank is filled with liquid; third, when the tank is discharged, and fourth, when the tank is pressurized.
If the pointer of differential pressure gauge deviates from zero, the zero adjustment of pointer can be carried out. Ninth faults and treatment methods can be seen in detail".
4. The combined control valve should not be in equilibrium for a long time. In the equilibrium state, the gas pipeline is connected with the liquid phase pipeline to form a pressurization loop, which has a small supercharging effect on the gas phase space of the tank. Therefore, when the balance state completes its function, the control valve should be immediately restored to the closed or open state. The operator should pay special attention to the operation except carefully following the operation mentioned above.
Six. Online disassembly differential pressure gauge and pressure gauge
The pressure gauge and differential pressure gauge can be removed on line when the tank is normally ventilated.
(1) on-line disassembly pressure gauge
The MZF- II type combination control valve is in the closed state.
The pressure gauge is removed with a fixed wrench (S17) blocking pressure gauge with opposite side dimensions (17mm) and a fixed wrench (S24) loosening pressure gauge locking nut with the opposite side 24mm (see Figure six MZF- II type combination control valve connection diagram).
(2) on-line disassembly differential pressure gauge
The MZF- II type combination control valve is in the closed state.
Take out the 4 M8 screws (see Figure five posterior view, 4- mm 10 through hole).
Take off two differential pressure gauge locking nuts (S22) (see Figure four right view).
Take the 4 M6 block connection screws (see Fig. five rear view), and then CYJ type double bellows differential pressure gauge is recommended.
(1) if the gas leakage is found in the rotating handle, the locking nut at the handle can be tightened in clockwise direction (see Figure six MZF- II type combination control valve connection diagram). The handle of the product is flexible and the pneumatic sealing performance is good, and the nut must not be locked too forcibly.
(2) MZF- II type combination control valve has good performance of opening and closing. It is not necessary to open and close too hard to avoid sticking.
Function equivalent diagram of eight and MZF- type combination control valves
In the MZC- II A type combined differential pressure meter, the function of MZF- II type combination control valve is equal to the function of four valves, the upper valve, the lower valve, the balance valve and the pressure valve. The combination control valve can show the indication of differential pressure gauge and pressure gauge, or close the indication of differential pressure gauge and pressure gauge (see Figure two).