Qhxf-2000 Breathing Valve

• Media: Water
• Standard: Water Vapour Oil
• Certification: CCC, RoHS, ISO, CE
• Temperature: High Temperature
• Connection: Flange
• Valve Seat: Double-Seat
• Model NO.: QHXF-2000
• Structure: Piston
• Material: Cast Iron
• Transport Package: Wooden Box
• Specification: DN15-DN800
• Trademark: XC
• Origin: China
• HS Code: 8421219990
• Production Capacity: 9999

Product Description

QHXF-2000 antifreeze breathing valve is a valve that not only ensures that the storage tank space is isolated from the atmosphere within a certain pressure range, but also can communicate with the atmosphere (breathing) when exceeding or below this pressure range. Its function is to prevent the tank from being damaged due to overpressure or vacuum, and at the same time can reduce the evaporation loss of storage liquid. It is mainly composed of valve seat, valve cover, protective cover and two groups of opening and closing devices controlled by vacuum and pressure. The opening and closing device includes valve disc, guide rod, spring, spring seat and sealing ring, etc. When the pressure in the tank reaches the rated positive exhaled pressure, the pressure valve flap opens and the steam in the tank is discharged; When the vacuum degree in the tank reaches the rated suction negative pressure, the vacuum valve flap opens and the air enters.

Working principle of antifreeze breathing valve

When the pressure of the medium in the tank is within the control operating pressure range of the QHXF-2000 antifreeze breathing valve, the breathing valve does not work to maintain the tightness of the oil tank;
When the medium is added to the tank, the pressure of the upper gas space in the tank rises, and the operating positive pressure of the breathing valve is reached. When the pressure valve is opened, the gas escapes from the breathing valve outlet, so that the pressure in the tank is not continued to increase, and the atmosphere outside the tank will open the negative pressure valve disc of the breathing valve.

What is the role of antifreeze breathing valve

QHXF-2000 antifreeze breathing valve is to maintain the tank air pressure balance, reduce the media volatilization safety and energy saving products, breathing valve make full use of the tank itself pressure capacity to reduce media emissions, the principle is to use the weight of the positive and negative pressure valve disc to control the tank exhaust positive pressure and suction negative pressure; When the medium is pumped out of the tank, the pressure of the upper gas space in the tank drops, and the operating negative pressure of the breathing valve is reached, the atmosphere outside the tank will top open the negative pressure valve disc top open, so that the outside gas enters the tank, so that the pressure in the tank no longer continues to fall, so that the pressure balance between the tank and the tank outside is balanced to protect the safety device of the storage tank.

How to install the antifreeze breathing valve

1, remove the packaging, read the product description this is crucial.
2. When hoisting the breathing valve, appropriate lifting tools should be selected to avoid damage to the protective cap of the breathing valve disc.
3. Check the coaxiality and verticality of the tube flange on the tank or water tank, which is essential for the normal use of the pressure vacuum relief valve (breathing valve).
4, check the water line surface of the tube flange on the tank or tank. It must be clean, free of scratches, corrosion, tool marks, and flat.
5. Remove the flange port protection cover and other packing materials.
6. Check the gasket; Make sure the material is suitable for the application.
7 Use the bolt circle to center the washer.

How to select the antifreeze breather valve

1, the requirements of the installation position and the temperature range, such as cold areas should be selected all-weather breathing valve, and installed in the pipeline should be selected pipe breathing valve.
2, the control pressure of the mechanical breathing valve should be adapted to the relevant pressure capacity.
3, the specifications of the mechanical breathing valve (flange diameter) should meet the requirements of the maximum inlet and outlet oil breathing gas flow of the oil tank.

The discharge calculation of antifreeze breathing valve

The breathing emission of the fixed top tank can be estimated as follows:
LB (M = 0.191, P/(100910 - P)) ^ ^ 1.73 x 0.68 x D H ^ 0.51 x delta T ^ 0.45 * C * FP KC
Where: LB- respiratory emission of fixed top tank (Kg/a);
M- molecular weight of the vapor in the tank;
P- the true vapor pressure (Pa) in a large liquid state;
D- diameter of the tank (m);
H- average vapor space height (m);
△T- the average temperature difference in a day (° C);
FP- coating factor (dimensionless), between 1 and 1.5 depending on the paint condition;
C- regulator for small diameter tanks (dimensionless); For tanks between 0 and 9m in diameter, C=1-0.0123(D-9)^2; C=1 for tanks with diameters greater than 9m;
KC- product factor (0.65 for petroleum crude oil KC, 1.0 for other organic liquids)
Work emissions are losses due to artificial loading and unloading. As a result of loading, when the pressure in the tank exceeds the release pressure, the steam is pressed out of the tank; The discharge loss occurs in the liquid level discharge, the air is pumped into the tank, because the air into the organic vapor saturated gas and expansion, thus exceeding the capacity of the steam space.
Working emissions from a fixed top tank can be estimated by the following formula:
LW = 4.188 * 10 ^ 7 * M * KN * P KC
Where: LW- Work loss of fixed top tank (Kg/m3 input)
KN- Turnover factor (dimensionless), the value is determined by the number of turnover per year (K). Number of turns = annual input/tank capacity
K<=36,KN=136
K > 220 KN = 0.26

6, How to maintain the antifreeze breather valve

QHXF-2000 antifreeze breather valve maintenance and maintenance once a month, twice a month in winter. The method: first gently open the valve cover, take out the vacuum valve disc and pressure valve disc, check the valve disc and valve disc seal, valve disc guide rod and guide rod sleeve without oil and dirt, such as oil and dirt should be removed, and then put back in place, pull up and down a few times, check whether the opening is flexible and reliable. If everything is normal, then the valve cover cover tight. In the maintenance and maintenance, if the valve disc is found to have scratches, wear and other abnormal phenomena, it should be replaced immediately or contacted with the supplier company to solve it in time.