What Is a Flap Valve?

The air volume regulating valve is also called the air regulating valve. It is an indispensable central air conditioner end fitting in the ventilation, air conditioning and air purification projects of civil buildings in industrial plants. For mixed adjustment of fresh air and return air.

(1) Nozzle size of folio multi-leaf air volume regulating valve and national

(1) The air volume regulating valve is unified in four specifications in the blade width. The blade shape is diamond-shaped double blades. The blades are soft overlapped, so the sealing performance is good.

(2) 2mm for air volume adjustment valve body frame

It is widely used in industrial, mining, and civil building HVAC systems to precisely regulate the air flow rate. It is one of the key devices to achieve ventilation control in various environments. Its main features are flexible operation, low noise, and small leakage. (Closed leakage <0.5%) Wide operating temperature range, reliable structure, safe and convenient ^[2]

The air volume regulating valve is generally divided into the following types:

(1) Folio valve,

(2) Butterfly valve (single leaf regulating valve),

(3) Open the regulating valve ^[2]

The installation of the air volume regulating valve was carried out in accordance with the national building standard design "Selection and Installation of Air Valves". described as follows:

1. For the air valve products delivered to the construction site, the installation unit shall report to the supervision and acceptance, and check the product model, specifications, materials, identification and specifications one by one according to the packing list, unpacking inspection certificate, test report and installation instruction documents. Whether the control method meets the requirements of design documents, and records should be made and signed by all parties.

2. Before the damper is installed in place, it should be tested one by one for its firmness and tightness. The switch operation test should be performed to check whether it is flexible and reliable. The electric damper should be tested and tested one by one and the test records should be made.

3. Before the air valve is in place, it must be checked whether its applicable scope, installation position, air flow direction and operating surface are correct.

4. The opening and closing direction and opening angle of the air valve should be accurately marked on the visible surface.

5. For the air valve installed at a high place, the manual control device should be 1.5-1.8m away from the exposed or operating platform.

6. The effective distance of the operating surface of the damper from the wall, ceiling and other equipment and pipes must not be less than 200mm, and the damper should not be installed in the structure layer or hole. The width of the seam around the valve should be greater than 150mm.

7. Check whether the flange size, bore diameter and hole distance of the connecting duct, the flatness and parallelism of the flange surface, the gasket material and thickness, and the connection method of the non-metal duct are in compliance with the requirements.

8. Check whether the positions and practices of supports and hangers meet the requirements of the specification or design documents. Separate supports and hangers should be provided for a single piece of damper with a weight of more than 50kg; separate supports and hangers should generally be provided for electric dampers; separate supports and hangers should also be provided for dampers for soft non-metallic duct systems .

9. Before installing the air valve for clean ventilation system, the inner surface of the valve body must be cleaned according to requirements, and the two ends shall be closed after the corresponding cleanliness standard is reached, and the sealing plate can be removed after it is in place. The inner surface of the air valve of the scrubbing and purifying air conditioning system should be made of fiber-free materials. The air damper after scrubbing and cleaning must not be stored in rooms without walls, floors, doors and windows. The temporary storage place must be kept clean.

10. In addition to the insulation of the damper whose temperature of the conveying medium exceeds 80 , the expansion compensation measures and protective measures should be carefully checked.

11. If the damper blade shaft of the damper located behind the effective filter in the purification system is exposed, the gap between it and the valve should be sealed to ensure that it does not leak.

12. Galvanized parts shall be used to connect the air valve to the air pipe flange, thin steel plate flange or fasteners that cannot be connected by blue. Except for the damper of galvanized sheet material, the damper connector of stainless steel or aluminum alloy should be made of the same material, and if its support and hanger are made of steel, anti-corrosive wood pads with a thickness of not less than 60mm or 5mm rubber sheet Gasket to insulate the valve body.

13. When the thickness design of flange gasket is not specified, it is generally not less than 3mm; the gasket should not protrude into the valve and should not protrude beyond the flange. The flange gasket of the purification system should be selected with good elasticity, air tightness and no dust production. Materials such as rubber plates or silicone plates are strictly prohibited from using foamed plastic, cardboard, asbestos rope, lead linseed and linoleum paper, which contain open pores and are easy to produce dust. The thickness of the gasket is determined by the elasticity of the material, which is generally 4-6mm. The specifications, performance and thickness of the gasket of a pair of flanges should be the same. It is strictly forbidden to paint on the gasket. The flange seal is to minimize the joints, and the joints shall be stepped or grooved and coated with sealant.

14. The horizontal error of the air valve installation is not more than 3%, and the vertical error is not more than 2%. The installation tolerance of the air valve without separate support and hanger is controlled together with the air pipe to control the accuracy. The connection of flanged air duct with thin steel plate shall meet the following requirements:

(1) The connection is complete and free of defects, and the surface should be flat and without obvious distortion.

(2) The distance between spring clips or fastening bolts should not be greater than 150mm, and they should be evenly distributed without loosening.

15. After installation of the air valve, the tightness test and test are usually performed together with the air pipe system. Tightness test (generally for light leakage test and single valve test operation). After the system is commissioned, the opening angle of each damper should be clearly marked with color paint and recorded.

16.Specific requirements for multi-leaf air volume regulating valve

(1) Check whether the opening angle of the valve disc matches the indicated position.

(2) Rotate the handle or start the air valve, and check whether the valve disc rubs against the valve body.

(3) Whether the seal is held firmly and tightly.

17. Installation inspection and test content of electric valve:

(1) Insulation resistance, grounding resistance, and withstand voltage.

(2) AC / DC working voltage is stable.

(3) Static and dynamic (maximum pressure difference) power measurement.

(4) Control and feedback signal test ^[3] .