Pump controls and valves

The vice president of the company Mr Big boss just came to his plant for site visit and watch the plant performances and production personally.  The plant manager asked Bud (the instrument engineer) to escort Mr Big boss around the factory with him. The Big boss saw one of the pump operated and asked the plant manager what is it

Big boss: What is this thing called? This stuff is make a lot of noise and vibration.

Plant manager: This is pump boss. Pumps are used in the production facilities to move liquid from a low pressure/elevation to one of higher pressure or elevation.

Big boss: How this thing works?

Control Valve operation and design criteria for beginners 3

In process systems, the final control element is normally a pneumatically actuated control valve. The control valve is subject to the hardest condition, the most expensive item and the most prone to incorrect selection.

There is no glamour in the control valve like there is in distributed control systems. Would any new engineer that graduated from distinguished University be interested in pipe, gasket, flanges, and packing and bothered working with dirt, mud, oilywater when “interfaced” with hardened stainless steel valve trim. It is also hard to hide a 400lb valve under your coat if you make mistake in sizing and selection and the valve needs to be changes.

Fig 1 Debris was found inside the control valve between the plug and seat ring

Fig 2. valve cage

But there are some reason for using valves.  they work and they are great to stand on for you to reach field mounted transmitter reached. If you are still interested, the following subject may be important for choosing the right control valve.

Control Valve Operation and Design Criteria for Beginners 2

Today, control valve can be sized easily by using software in a PC, but in the reality 83.43% of the control valve are sized incorrectly. 76.1 % are too big, 5.13% are too small, 2.2% are both (hahaha). The reason is lack of understanding about vapour pressure (which makes valve cavitate and flash), fluid property (if the service is slurry, the slurry can block the trim and everybody thinks that the valve is undersize) ,and all the things that are mentioned in the flow chart

If the valve is sized incorrectly and the valve needs to be changed, everybody will know it. And it is hard to change it insitu, not including how to perform the seat leak test when the valve had been changed.

Orifice (Differential Pressure) Flow meter Design 1

For Flow meters selection and sizing, use the orifice flow meter. You will waste some energy and money but at least you can relate to its principle of measurement. It is also requires a basic philosophy and prejudice. The most popular method of the flowmeter selection is to use an orifice unless it won’t work.

Reason for using orifice (DP flow transmitter)
Simple (but they are hard to install to get a good velocity profile)
Inexpensive (well there are cheap ultrasonic flowmeters with better accuracy and turndown ratio than DP transmitter today)
Available in various sizes, type, and connections.
Simple design, rugged, and suitable for liquids, gases, steam.

Why am I writing a technical blog

Why am I writing a technical blog? I’m not trying to win a literary awards or become rich and famous ( Maybe I am trying to impress my friends, relatives and associates a little bit). For me the most important thing is a sense of accomplishment to share what I have learned and insure it is not lost.

How do I get the idea out?

Two Phases Oil And Gas Separation Level Measurement

Produced wellhead fluids are complexes mixture of hydrocarbon liquid and gas with different physical characteristics such as density, vapor pressure, .. etc.

Therefore the physical separation between three phases ( water, oil, and gas) is one of the basic production, processing, and treatment in oil and gas facilities.

Separator where mainly designed for mechanically separate liquid hydrocarbon and gases at specific temperature and pressure.

Proper design for separator ( including the instrumentation) is important because separation vessel is normally the initial processing vessel at any facilities.

Oh you’re an Instrument Engineer, The chosen Few (hahaha)

No one plans to become an instrument engineer.The prospective instrument engineer doesn’t even know the profession exists until the job offer comes. Public understanding to the profession is nonexistent.

Do you got What it takes to become an instrument engineer? Do you like to read hundreds pages of catalogs? Do you like to keep track with thousands of instrumentation that changes yearly? Are you capable of forgetting all the math you learned in college?

Being an Instrument engineer is like being paid to go shopping to your nearest electronics or computer store with someone else money.


What is unfortune is that the experienced engineers typically don’t like to speak in public or write. The result is a shortage of good mentors and instructors.