Flowmeters
Flow Meter itu menurut
www.omega.com, bisa dibagi empat:
1.
D/P Flowmeter : Flowmeter yg prinsip kerjanya menggunakan perbedaan tekanan antara sisi upstream dan downstream, yg kemudian di konversi menjadi indikasi flow. Yg termasuk ke dalam D/P flowmeter antara lain:
a.
Primary/Head Flow Element, contohnya: Orifice plate, venture/flow tube, flow nozzle, segmental wedge dan venture cone.
b.
Pitot Tubes, contohnya: Annubar
c.
Variable Area Flowmeter, contohnya: Rotameter
2.
Mechanical Flowmetera.
Positive Displacement Flowmeter, contohnya: Liquid PD Meter, Piston Meter, Gear & Lobe Meter, Helix Meter, Gas PD Meter dsb.
b.
Turbine Flowmeterc.
Other Rotary Flowmeter, contohnya: propeller meter, paddlewheel flowmeter
3.
Electronic Flowmetera.
Magnetic Flowmeterb.
Vortex Flowmeterc.
Ultrasonic Flowmeter4.
Mass Flowmetera.
Coriolis Flowmeterb.
Thermal Mass Flowmeterc.
Hot-Wire Anemometer
Safety Valve
Frankly speaking, until now, sometimes I confused with so many terminologies about safety valve, relief valve, safety relief valve, pressure safety valve or pressure relief valve. But after searching some valid references such as international standards and
www.spiraxsarco.com I think I can divide those terms clearly. well, I hope this article will be useful for you.
1. IntroductionThe primary function of safety valve is to protect LIFE and PROPERTY
How? by releasing a volume of fluid from within the plant when predetermined maximum pressure is reached.
TerminologyPresure Relief Valve is a spring loaded pressure relief device designed to open and relieve excess pressure and to re-close and prevent the further flow of fluid after normal conditions have been restored.
Safety Vavle is a pressure relief valve actuated by inlet static pressure and characterized by rapid opening or pop action. Normally used for compressible gases, steam or air services.
Relief Valve is a pressure reliev valve actuated by inlet static pressure and having a gradual lift generally proportional to the increase of overpressure. Primarily used with incompressible fluids.
Safety Relief Valve is a pressure relief valve that may be used for safety or relief valve depending on the application.
Ok, from above definitions, I hope you can clearly differ the terminology.
Discharge CapacityFlow Area : The minimum cross sectional area between inlet and the seat, at its narrowest point.
Curtain Area : The area of cylindrical or conical discharge opening between the seating surfaces created by the lift of the disk above the seat.
Discharge Area: This is the lesser og the curtain area or flow area, which determines the flow thru the valve
Sorry, I can't continue the blog right now, I have to go...
to be continue...
Reynolds Number
Re = (Velocity X Pipe Diameter X Density)/absolute Viscosity
Re < 2000 Laminar flow, 'coz viscous forces predominantly
2000 < Re < 4000 Transitional Flow
Re > 4000 Turbulent Flow, 'coz inertial forces predominantly
