In some process design, I saw the low/high select signal input to relay to select the source of output signal. The signal may come from HIC or from two controllers (i.e.one from temperature controller and another come from pressure controller)to compare the signal at the relay. How can we...
I've just wonder the function of HIC (Hand indicate controller). Is it used to manual open for control valve,etc during startup or shutdown in process or...? In some design, the system have a control valve which can operate in "AUTO" and "Manual" mode why do we need to have HIC to manual open or...
Please any expert explain when operating reciprocating pump. If the process require flow rate with lower pressure than discharge pressure from pump. Let's say required pressure = 5 barg but discharge from pump is 414 barg. How can we reduce pressure? Is it adjustable to achieve the desired value...
Anyone please help explain the function of pressure different switch low low (PDSLL) between the suction and discharge of cryogenic pump. Is it use to protect the pump? or I mean the real reason to have it.
Thanks.
Anyone can explain the function of pressure different switch low low (PDSLL) between the suction and discharge of cryogenic pump. Is it use to protect the pump? or I mean the real reason to have it.
Thanks.
When sizing the control valve and after calculate the actual pressure drop of system and maximum allowable pressure drop of control valve, found that actual pressure drop less than max.allowable. Then select the actual pressure drop to size the control valve but the result shown that the...
Please anyone who know where to find the specification of SIVL (super insulated vacuum line)for cryogenic liquid (pipe id., od.,etc)
Thanks in advance for suggestion.
1.Can any expert help explain, what is the minimum required flow rate of pump?
2.In the situation that we have to throttle the discharge flow because the rated flow is not at the intersection of pump curve and system curve(the rated flow is less than the flow at the intersected point, do we...
Please any pump expert explain the term of run-out condition? How it has been occured? and Does it have a criteria to select the max.flow rate, normal and min.flow rate for pump to operate?
Thanks in advance.
Is there anybody know how much we can trim the diameter of impeller in percentage(Any limit to the original size)? And can we bring the affinity law to calculate the pump characteristic curve at reduce impeller size? Please suggust!
1)When we have the system of transfer liquid with using centrifugal pump which suction line connected from storage tanks and liquid is discharged to the process column, since the required flow rate is less than the point that performance curve meet the system curve.(Pump will operate at that...
Please anyone who know suggest me with below information ;
1. What is the difference meaning between the pressure drop and differential pressure of control valve?
2. When making a hydraulic calculation example for transfer liquid with pump,how can we know the suitable pressure drop of control...
I am designing the cryogenic liquid injection system and bring an old pump to use. The discharge line will be tied-in to the existing pipeline which have a flow control valve and orifice. I can not find the pressure drop of that control valve to include in the system pressure drop.(No...
Any expert, please explain me the characteristic between pressure and flow control valve. Is there anythings different to size for these 2 control valves. I mean the criterion for sizing of valve, if the condition of this 2 types of valves are same.
Please give suggestion. Thanks.
What is the different between thermal expansion valve and thermal relief valve, if the fluid is liquid nitrogen(LIN)in one metre of 2" stainless pipe with SIVL insulation (LIN is in pipe between the block valve and non-return valve). What type of relief valve should I use to protect for the...
Would someone recommend the solution or criteria for calculation of relief flow rate to size the thermal expansion valve, fluid is liquid nitrogen in one metre of 2" stainless pipe with SIVL insulation. In case of the failure of insulation, temperature of fluid will be higher, let say 50 degC. I...
Would someone give the solution for sizing of the thermal expansion valve, imagine that liquid nitrogen is in one metre of 2" stainless pipe with insulation. If the insulation is out of order or the ambient temperature is higher, let say 35 degC. I mean what recommended equation should i have to...
