Yes, it would mean opening the valve by force.
Interested in Language
Hello all forum users!
WARNING! As per SOLAS-requirements, check-lifting must be carried out before loading, discharging and ballasting is commenced. If the valve disc does not move freely, the cause should be determined and corrected immediately. If a lever is used, cracking the valve open would not be adequate evidence that it is in proper working condition. It is likely clogged.
In my opinion, the underlined fragment in bold type means the following:
If a lever is used, opening the valve (by force) would not provide adequate evidence that the valve is in proper working condition.
The fragment is taken from operating/maintenance instructions for HS-ISO pressure valve.
I am particularly interested in the meaning "to crack something open. I think it means "to open something by force" and is similar in meaning to "to break something open". I may be wrong.
While certainly not familiar with the operation, in the context provided I would agree with your interpretation.
I don't associate force with opening beer cans either. If you crack open the door, you open the door a crack.
I assumed that "cracking the valve open" meant only opening it a tiny bit.
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.
As a retired NES chemical engineer (oil, gas and petrochemical industries), but not a teacher:
Cracking a valve open very specifically means opening it a small amount. It does not, per se, imply any significant force is used.
Almost all 1/4-turn on/off valves (e.g. ball/plug valves) have a lever, which is, traditionally in line with the pipe when open and at right angles to it when closed. Those that don't have a physical lever would likely have an actuator to perform the same duty.
Last edited by Route21; 18-May-2013 at 12:38. Reason: added "per se".
PS SOLAS stands for Safety of life at sea. In situations where timing is critical, I would expect to see primarily ball valves used as they are quick to operate.
Last edited by Route21; 18-May-2013 at 12:54.
The OP mentions "pressure valve" and "disc".
If, by that, the OP actually means a "Pressure Relief Valve" (PRV), that might explain the reference to a "disc".
What the O&M manual could be saying is that, just because you can actually "lift" (move) the spring-loaded disc, it doesn't mean that the PRV will be able to open sufficiently to relieve any overpressure. Without details of the system from the OP, it's not possible to see where any overpressure or fouling would come from.
The thing that I find confusing from the OP was that I would not expect to see an unprotected, fouled relief valve, particularly in a SOLAS situation, where lives are at risk. I would expect the inlet of the relief valve to be protected by a carbon or metal "rupture/bursting disc", with a pressure gauge between the disc and the PRV, to identify if the disc had blown. If it has, the PRV should be removed, cleaned and "popped", to ensure it opens and closes at the correct pressures.
PS The OP should be able to understand the technicalities in these posts.
Last edited by Route21; 18-May-2013 at 14:22. Reason: added wiki reference to relief valves and comments on bursting discs.