By Gobind Khiani – Consulting Fellow-Piping/Pipelines


Case 1:

Trapped water or liquid in valve cavity got frozen in winter and caused sealing parts damage.

Solutions & Suggestions:

1. Drain the valve thoroughly when system unit shut down during wintertime.

2. Add heat tracing system for the pipeline.


Case 2:

Check valve disc chattering in the gas plant caused impact noise, and even sealing failure.

Solutions & Suggestions:

1. Installation place modification to guarantee the minimum upstream and downstream straight pipeline length.

2. Add damper device as buffer.


Case 3:

Freezing occurred in the packing box of the valve for cryogenic service, resulting in stem leakage.

Solutions & Suggestions:

Modify the installation orientation with maximum slope 45° for cryogenic liquid service valves


Case 4:

Inappropriate insulation height for cryogenic valve caused stem leakage.

Solutions & Suggestions:

Modify insulation height up-to vapor dissipation space for low temperature service.


Case 5:

Ball valve applied to regulate the flow in the pipeline caused the sealing performance failure.

Solutions & Suggestions:

1. Never use gate or ball valves to regulate the flow to ensure proper service life.

2. Globe and butterfly valves could be used for regulating function for pipeline.


Case 6:

Oxygen service valves are at risk of on-site accidents if not strictly cleaned and protected.

Solutions & Suggestions:

1. Valves will be totally cleaned, reassembled, retested and seal packed in clean room.

2. Before installation, do not open the package.

3. Keep the valve passage clean during installation.

4. Do not fast operate the valve under full pressure difference.