General Infomation G-0005
3. Procedure
Management factor and Procedure are different depending on gasket material.
Refer to Approval drawing of subject product for the gasket material.
3.1 In the case of Joint sheets (Non-asbestos)
| Management factor: | Tightening torque |
| Procedure: | Tightening is to be conducted by 3 steps. Step 1: 50% of specified torque Step 2: 80% of specified torque Step 3: 100% of specified torque The maximum tightening torque is referred to Table 1. Tightening is to be conducted by diagonal order. (Refer to Fig.1) |
3.2 In the case of Vortex gaskets
| Management factor: | Thickness of gasket after tightening |
| Procedure: | The tightening is managed by the gap of two flanges. Tighten the bolts and nuts upto the condition that the thickness of gasket becomes 3.3±0.1 mm. (The thickness of gasket is 4.5 mm when no stress is given.) Tightening is to be conducted by diagonal order. As per 3.1. |
Table 1. Tightening torque of bots and nuts
| Nominal size of bolts | Tightening torque | |
|---|---|---|
| M10 | 25 N·m | 250 kgf·cm |
| M12 | 50 | 500 |
| M16 | 120 | 1200 |
| M20 | 180 | 1800 |
| M22 | 260 | 2600 |
Cautions;
| 1. Material of gasket: | Joint sheets (Non-asbestos) |
| 2. Material of Bolts and Nuts: | SS400 or SUS304 |
| 3. Allowance of tightening torque: | ±20% |
Fig. 1. Order of tightening of Bolts (Nuts)
