Marine Fixed type Mushroom Ventilators CB/T 4444-2017 Type D

Marine Fixed type Mushroom Ventilators CB/T 4444-2017 Type D

Mushroom Ventilator is installed on deck for natural ventilation or mechanical ventilation devices .

CB/T 4444-2017 Mushroom Ventilation is generally used for kitchen and accommodation of ventilator regulating screw, simply turn adjusting handwheel indoors can reach the purpose of adjusting the opening size.

CB/T 4444-2017 is a new edition of CB/T 295-2000, type D of CB/T 4444 is an additional model/pattern compare to CB/T 295.

Process requirements

1. Surface: should be flat and smooth, without sharp edges, distortion, or skew.

2. Size error:  ±3mm, and the deviation of the verticality is 2/h1000 (h is the height of the ventilator cylinder)

3. The welding surface: free of cracks, slag inclusions, burn-through, and unfused defects.

4. The opening of the weather-tight cover of the fungus-shaped ventilator for ships should be flexible, and the movable part should be coated with neutral lubricating grease.

5. Derusting: the internal and external surfaces of the steel parts of the fungus-shaped ventilating cap should reach the Sa2 level or St2 level specified in GB/T8923, and then two antirust primers.

Structure descriptions:

1. Vent head

2. Sealing packing

3. Forced filling oil cup

4. Weather tight cover

5. Rat-proof, insect-proof net or fire net

6. Air pipe

7. Bevel gear

9. Hand wheel

10. Point stick

11. Screw rod

Obviously, type D CB/T 4444's opening & closing is operating from inside, other type A,B,C and E is available.

Type D CB/T 4444-2017 Models: