valve inspection

JB/T9092 specifies the valve inspection and pressure test requirements.  Suitable for metal seal pair, elastic seal pair and non-metal seal pair (such as ceramic) gate valve, globe valve, plug valve, ball valve, check valve and butterfly valve inspection and pressure test.  It can also be applied to other types of valves with the consent of both parties.  

Elastic seal pair refers to:  

· Soft seal pair, solid and semi-solid grease pair (e.g. oil seal plug valve)  

· Sealing pair composed of non-metallic and metallic materials  

JB/T7927-1999 Valve cast steel appearance quality requirements:  

One-way seal: After the valve is closed, the medium must enter from both ends of the valve in a certain direction, the valve seal pair to keep sealed  

Bidirectional seal: No matter which direction the medium enters from both ends of the valve, the valve seal pair can maintain the seal after the valve is closed  

Valve inspection requirements:  

- Inspection at valve factory  

As stipulated in the order contract, the buyer shall inspect the valves at the factory, and the buyer's inspector may enter the factory for inspection at any time during the manufacture of the ordered valves  

- Inspection outside the valve factory  

If Buyer specifies that the inspection includes housing parts manufactured outside the valve manufacturer, these parts shall be inspected by Buyer's inspector at their original manufacturer  

- Check Notifications  

When the Buyer requests inspection, the valve manufacturer shall inform the Buyer at the address listed in the order contract 7 days prior to the inspection according to the test items required.  If the inspection is required outside the valve manufacturer, the manufacturer shall also notify the Buyer 7 days in advance  

- Scope of inspection  

If no additional items are specified in the order contract, the Buyer's inspection shall be limited to the following:  

1. According to the order contract, use non-destructive inspection tools and methods to check the valve during assembly  

2. "Necessary" and "optional" pressure tests  

3. Review processing records and NDE records (including required radiographic records)  

Note: All inspections shall be conducted in accordance with written procedures prepared in accordance with the corresponding standards  

- Inspection  

1. The valve manufacturer shall inspect the appearance of all the casting parts of the valve body, valve cover and sealing parts to ensure that they meet the provisions of JB/T7929  

2. The valve manufacturer shall inspect each valve to ensure compliance with this standard and relevant product standards  

- Supplementary inspection  

Other supplementary inspections shall be carried out in accordance with the procedures and requirements agreed upon by the Buyer and the seller and shall be carried out by the manufacturer in the presence of the Buyer's inspector  

Valve pressure test requirements  

- Test Site  

The pressure test shall be conducted by the valve manufacturer in the valve factory  

- Test equipment  

Equipment used to perform pressure tests shall be tested without external forces affecting seat sealing  

- Test requirements  

1. Each valve shall be subjected to pressure test according to the requirements of Table 1 or Table 2  

2. Valves with nominal diameter less than or equal to 100mm, nominal pressure less than or equal to 25.0MPa, nominal diameter greater than or equal to 125mm, nominal pressure less than or equal to 10.0Mpa should be tested according to Table 1  

3. Valves with nominal diameter less than or equal to 100mm and nominal pressure greater than 25.0Mpa and nominal diameter greater than or equal to 125mm and nominal pressure greater than 10.0Mpa should be tested according to Table 2