**1. Failure to Confirm Complete Depressurization Before Installation**
If residual pressure remains in the pipeline, inserting or switching the blind plate may cause mechanical impact or damage to sealing surfaces.
If Line Blind Valve operation is performed without full depressurization, it may result in:
Therefore, the standard procedure requires: full depressurization, complete venting of residual media, and confirmation of zero-pressure conditions before isolation operation.
## **2. Installing Line Blind Valve with Poor Flange Alignment**
Line Blind Valve systems depend on accurate flange alignment.
If significant misalignment is present, the Line Blind Valve should not be forced into installation. Pipe supports or alignment conditions must be corrected first.
Line Blind Valve sealing performance typically relies on metal-to-metal sealing or soft sealing structures.
Then effective sealing cannot be achieved even if the design torque is applied.
From an engineering perspective: if the sealing surface is not clean, micro-leakage is inevitable.
Some Line Blind Valve designs have specific flow direction or installation orientation requirements.
Installation must strictly follow manufacturer markings (flow arrow or structural orientation), not field experience assumptions.
Line Blind Valve systems typically require axial clamping force via bolts or handwheel mechanisms.
Therefore, torque must remain within the specified design range. Higher torque does not improve sealing reliability.
## **6. Forced Operation Under High Temperature Conditions**
At elevated temperatures, thermal expansion affects blind plate insertion and operation.
●Lack of thermal clearance may damage sealing surfaces due to compression
Standard practice is to perform Line Blind Valve operation only after the system cools to a safe operating temperature range.
Although Line Blind Valve devices are rigid structures, pipeline systems are subject to thermal expansion and vibration.
For long-distance pipelines or high-temperature systems, proper support design is required to ensure stable operation of the Line Blind Valve.
## **8. Skipping Leakage Testing and Verification**
In many installations, systems are put into service without proper testing.
Then minor leaks may remain undetected and escalate over time.
The core requirement of Line Blind Valve installation is not mechanical assembly, but **ensuring reliable positive isolation**.
If pressure is not fully released, operation must not proceed.