In tank installations, what is not permitted regarding pipe flanges?

The use of pipe flanges in tank installations is governed by safety and integrity regulations. When it comes to using shims, it is not permitted because shims may compromise the compressive seal necessary for flanges. This could lead to improper alignment and sealing issues, risking leaks which could pose safety hazards and environmental concerns.

Ensuring a tight and secure joint is critical when installing flanged connections in tanks that hold fuel or other liquids. Instead, methods like the application of Teflon tape on threaded connections or the use of robust welding techniques are seen as acceptable because they contribute to enhanced sealing and joint integrity under pressure.