Test Bench operation - proper procedure for 598

[Gorman3]

What is the proper procedure for performing API 598 low pressure (80 psi) on a gate valve using a test bench, the type that can turn the valve from vertical to horizontal for air test purpose. I've seen it done 2 ways

Example for a 6" 150# API 600

1. The valve is half open and clamped only on the right side. Air is running through at 80 psi. Whilst air is running the valve is closed manually. Right side air pressure will read 80, valve is rotated to horizontal water poured in watch bubbles etc

2. Valve is half open clamped on both sides. Air is pumped in from the right while sealed by the left clamp. Air hits 80 psi and it is locked down. Air input hose is locked Left side clamp comes off, valve rotated horizontal filled w/ water etc.

Which of these 2 is the proper procedure? I've seen it done both ways.

 

[reverman]

If I understand correctly than #1 is the correct test. The air pressure should be constantly supplied.

#2 is "Trapping" the pressure. Stopping air supply is not acceptable. Paragraph 6.4.4 of API 598 forbids it