Nitrogen seal valve working principle:

Nitrogen seal valve without additional energy, the use of the regulated medium's own energy as a power source. Automatic control of the valve medium flow, so that the pressure after the valve to maintain a constant pressure stabilization device. Valve itself internal through the spool, diaphragm, spring and other mechanical components of the mutual action to stabilize the pressure at the outlet P2.

Nitrogen seal valve work process: when the inlet P1 pressure rises, the outlet P2 pressure will have a tendency to rise, P2 pressure smile will rise through the diaphragm to the following large gas chamber, in the large diaphragm amplification, the spring will be compressed, then the spool connected to the spring will be connected to reduce the direction of the valve opening movement, so as to reduce the flow rate and the outlet pressure of P2, so as to achieve the outlet P2 pressure stabilization Purpose; and vice versa.

Nitrogen seal valve is a precise millibar level regulator, relative to the outlet pressure of the pressure regulator valve it will be much larger diaphragm, take the German Mankenberg pressure reducing valve DM762 as an example, 762 diaphragm diameter range from 220mm to 500mm, the export of the range of the pressure regulator corresponding to the range of 0.015-0.030bar to 0.1-0.52bar to the precise 0.002-0.003bar to 0.002bar. -0.003bar to 0.012-0.07bar, it can be seen that the bigger the diaphragm is, the smaller the stabilized value of outlet pressure is. Generally, nitrogen sealing valves have a control pipe and a leakage pipe. The control tube improves the sensitivity of the valve, while the leakage tube prevents the medium from leaking into the spring space after the diaphragm ruptures, and the leakage tube sends the medium back to the proper storage space instead of discharging it into the air.

In addition, when the through diameter is large and the flow rate is large, pilot-operated combination nitrogen seal valve can be used, generally used in large tanks. Pilot-operated nitrogen sealing valve is a combination of relief valve, millibar pressure reducing valve, filter and shut-off valve. Here is still the German Mankenberg company produced RP840 pilot nitrogen seal valve as an example.

RP840 is composed of a relief valve DV5.1, a pressure reducing valve DM762, 2 throttle valves and a filter dust collector.

DV5.1 can ensure a back pressure in the tank, when the tank nitrogen reduces the pressure drops, DM762 replenishes nitrogen to the tank; when the liquid level in the tank rises and the nitrogen is compressed the pressure increases, DV5.1 will release nitrogen outward at the set safety pressure point, but it will ensure a back pressure in the tank, and the pressure in the tank reaches the set point below DV5.1 will be closed.

Nitrogen sealing valve is composed of two main parts: ZZDG type conductor-operated self-operated pressure regulating valve (hereinafter referred to as nitrogen supply valve) and ZZDX type self-operated micro-pressure regulating valve (hereinafter referred to as nitrogen relief valve). When the pressure inside the tank rises above the set value, the nitrogen supply valve closes and the nitrogen relief valve opens (there is no breathing valve at the top of the tank, or the breathing valve fails to open), so that the excess pressure inside the tank can be released. When the pressure inside the tank decreases, the nitrogen relief valve is closed and the nitrogen supply valve opens to inject nitrogen into the tank. The pressure before the nitrogen supply valve should be below 1.0Mpa. If the pressure on the site is high, a ZZYP self-operated pressure regulating valve can be installed in front of the nitrogen supply valve to reduce the pressure to below 1.0 Mpa to improve the reliability and utilization effect.

Installation of nitrogen sealing valve: