Two systems are at different pressure 8 barg and 2 barg. Two systems are separated with a block valve (diaphragm valve manual) PN16 same as the piping system (10 barg @ 120 C)
I got a question: the pressure difference is too much, diaphragm valve is not good enough. In my opinion, as long as the valve is PN 16, it should be able to take 10 barg @ right temperature. The pressure difference is not a issue. But I didn't find information regarding to question.
I was wondering how HOLDS on a P&ID are usually used:
I regard the HOLDS as a To-Do List that gets smaller until the P&IDs can be issued for construction, so basically all pieces of information conveyed by the P&ID which still need to be confirmed (e.g. by vendor documentation, or a hydraulic calculation, input by another engineering discipline, decision by the client etc.) are marked with a cloud and a short explanation is given (stating what information is required and who is expected to provide it)
I’m always suspicious when I start a Detail Engineering Phase with a set of P&IDs that do not have HOLDS on them, as I know that the Process Engineer who prepared them in the Basic Engineering could not have been certain that all of the information conveyed in the P&ID are final (otherwise there would be no point in working on the P&IDs in the Detail Engineering Phase anymore at all) but chose not to write down what pieces of information are still missing, or to quote Donald Rumsfeld: “We also know there are known unknowns; that is to say we know there are some things we do not know. But there are also unknown unknowns—the ones we don't know we don't know.”
In my opinion by not using HOLDs, we create those “unknown unknowns”, which is a real problem, as the P&ID then suggests a stage of completion of the project that does not reflect reality, with the respective effects on the schedule and the necessary man hours.
Does this philosophy make sense in your opinion/experience?
We have some Spherical LPG storage tanks which are connected to 3 different remote pounding basins. Unfortunately the plant is old and we could not find design basis for basins. Because of change in regulations in germany, LPG considered hazardous to water and we need to cover the surface of basin with betone. My questions are:
1- Is there any EN or german regulation which describe how the volume of the basin shall be calculated ( I have seen in other posts people refering to API2510 but it is an american standard and we need to design according to european standard)
2- how this system shall be connected to waste water system to drain rainwater/firewater/foam? is it enough to conect it to sewer system with a water barrier and gas sensor ?
I am trying for procurement of silica gel with following specs.
Service- for drying instrument air @ 7 Bar.
Specifications for Silica Gel
Silica Gel charge Conforming to IS3401:1970
Quantity required -1500 Kg
Shape- Large Pores granular silica gel.
Size- 2.7 to 7.00 MM
Tolerance- +/- 5%
Bulk Density Kg/M3 (Dried at 150 DEG C)- 400-500
Moisture Absorption capacity @ 25DEG C & 100 % RH at EQ % W/W 70 (MIN)
FREE MOISTURE Content (Determined at 120 DEg C.)- Not more than 4 % BY WT.
Loss on Ignition % (Over 150DEG C) 4 (+/- 1)
Mechanical Strengtth % 86 (MIN)
CHLORIDE AS NaCL % 0.05
SULPHATE AS NA2SO4 % 0.25
However a vender says he has silica gel with BD of 500-650 kg/m3 & adsorption capacity of 50 % min
My question is
1. How BD affects adsorption capacity & surface area?
2. is it okay if I accept silica gel of 500-650 kg/M3 BD inplace of current spcs mentoned above ?
Any information regarding silica gel, its various properties is most welcome.
Is there any standard for labeling process vessel such as storage tank or distillation column? Label here referred to vessel name and tag number. I would like to know information such as font size, type, the back ground color.