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Posted on 08/02/08, under Aggregates & Mining, Automotive, Beverage, Bulk Solids Handling, Cement, Chemical, Dairy, Distillation of Alcohols, Environment & Recycling, Flour and Milling, Food, Information, Level Measurement, Marine Shipping Harbours, Offshore Oil & Gas, Other, Paper and Board, Petrochemical, Pharmaceuticals, Power Generation, Steels and Metal Manufacturing, Water and Waste · RSS · No Comments
Most of the choices and considerations for level controls discussed with customers are based largely on the criteria outlined below,
Any sensing, control, indication or detection consists of two main area’s
Do I need to know how much? What do I have in storage or do I need it for ‘controlling’ a process?
or
Do I just need to know when? Stop or start : Low level, dry running or high-level, overspill detection
Once decided upon, these are the other main criteria and questions to consider:
How important is this information – and what are the consequences?
It can be from the not very important, nice to know indication to a ‘safety interlocked plant shut down’. A plant could run out of important raw materials or be unable to despatch enough finished products to customers affecting cash flow. Maybe it could prevent a major pollution incident (from an effluent tank) saving thousands in fines (and reputation) or a simple saving of energy or plant equipment. (e.g. switching a pump when its not required)
What information is required? And in what format? A visual indication, or an alarm, flashing light, klaxon, a table on a computer screen, an automatic shut down, e-mail, text message or pager, a Fieldbus protocol to a main DCS system.
Who needs it? Someone or everyone? This information can be shared through the whole organisation:
- Plant operators walking past the vessel,
- Drivers at an offloading point,
- Central plant control system
- Production planners for future order fulfilling
- Distribution and logistics to coordinate deliveries,
- Accounts for stock valuation,
- Purchasing departments for re-ordering,
- Management for strategic decision,
- Sales team for customers placing orders
- Material suppliers/vendors to share information and schedule deliveries.
Accuracy? What size of tank, vessel or hopper range am I measuring over? What are the consequences (see above) Do I need the nearest millimetre or metre? Am I looking for a trend or an absolute accuracy of measurement?
What are the process conditions? These also need to be reviewed of course; temperatures, pressures, materials compatibility, process and product compatibility and behaviour, any special standards – for hygiene or safety certifications. What and where are the connections into the process and equipment, what is the access to the plant, are there preferences for contact or non-contact measurements…and how will this all interact with some of the criteria above?
The ‘connectivity’ is the next step. What is available for access, power, wiring, mounting of devices and local indicators, protocols for connecting to plant and pc networks, scheduling of the plant to be available for installation. Liaising with electrical departments and contractors for installation, mechanical personnel if vessel modifications are required, production for availability, perhaps IT people if the information is to be networked – as well as a commissioning engineer or can internal staff complete this?
After sales service, maintenance and support for the equipment. This is the final step but probably one of the most important and should be considered just as carefully BEFORE purchase; What is the warranty, what about obsolescence/compatibility, how easy is it to use, Is in house ‘competency training’ required, service contracts, remote connection/calibration and on going support for any issues or maintenance?
Experience
Above are only some basic points to consider as a guide, difficult for busy staff to get their heads around with all other work needs, but all of this and more is considered by a Specialist Level Engineer, who will discuss these options and more with customers every day. They can take people through all the options, steps and budget consequences, ensuring that all aspects are considered for the best outcomes to be secured. We are always happy to answer any questions customers have, so feel free to contact us if you have any question arising from this blog.
Next time we will cover some of the techniques of level measurement and the basic considerations.
Posted on 30/11/07, under Aggregates & Mining, Automotive, Beverage, Bulk Solids Handling, Cement, Chemical, Dairy, Distillation of Alcohols, Environment & Recycling, Flour and Milling, Food, Information, Level Measurement, Marine Shipping Harbours, Offshore Oil & Gas, Other, Paper and Board, Petrochemical, Pharmaceuticals, Power Generation, Steels and Metal Manufacturing, Water and Waste · RSS · 2 Comments
This is only from the level measurement and control perspective, but many of the points are just as transferable to other process measurement parameters which offer equally important information, such as temperature, flow, mass and pressure.
What is level measurement?
Level measurement is like any other piece of business information, that’s what it is – Business information, just like the customer database or accounts ledgers and can be just as important, if not more. For any business to function efficiently, safely and profitably it must have accurate information and be fit for purpose reliable and cost effective.
Terminologies in level measurement can vary greatly from industry to industry for liquids or bulk solids; i.e. referred to as ‘level: measurement, indication, sensing, control or gauging’ to name but a few. And vessel terminology varies too, e.g. tanks, vessels, mixers, reactors, pots, containers, chests, sumps, silos, bins and hoppers.
Level information can be utilised for supply of raw materials, in-process control or inventory of finished materials, all of which can be an indirect or direct major contribution to any manufacturing businesses’ profitability. Almost every industry uses level measurement and sensing, it touches our lives every day. Examples of where level measurement it is used in the petrol station forecourt with underground tanks, level controls of the water supply delivered to the tap and almost all foods and medicines we see in our stores, from washing of vegetables in food processors to complex reactor vessels mixing compounds in pharmaceutical plants we even control levels in a water ride at an adventure park. All these need level controls to ensure the product supplied to consumers is available and the correct quality and quantity.
Why is it so important?
In some cases we come across, the decision of what to use and how is left to last, a control and information system has been installed and levels are at the ‘end of the budget’. In our experience, whilst the money spent on information gathering systems like SCADA, DCS and IT systems, is of course important, if the information it is fed from field sensors isn’t reliable or accurate, then the whole systems value can be compromised, or at worst, useless.
By getting any measurement right first time, it can reduce costs, improve outcomes and increase the usefulness of the information it delivers.
The next blog post will look at choices and considerations for selection
Posted on 19/11/07, under Application News, Guided Microwave TDR, Level Interface, Level Measurement, Offshore Oil & Gas, VEGA Product News · RSS · No Comments
 VEGAFLEX 60 guided wave level radars are now “Quality System Approved“ (equivalent to a “Preferred Vendors List“) with Oil and Gas supplier Saudi Aramco, following a successful audit in July 2007. VEGA are now an official supplier for guided microwave level sensing devices from across a VEGAFLEX TDR range which includes level and interface devices, temperatures up to 400C and pressures to 400 Bar, ATEX approvals and SIL conformance as well as Profibus and FF versions as standard options.
Posted on 10/10/07, under Application News, Capacitive, Food, Guided Microwave TDR, Level Measurement, Level Switching, Pharmaceuticals, Pressure Measurement, Radar, VEGA Product News, Vibration Measurement Liquid Switches, Vibration Measurement Solid Switches · RSS · No Comments
 The plics® family will be extended by a new polished stainless steel housing. The polished housing surface is an ideal solution especially for applications in the food processing and pharmaceutical industry, being from the plics format, againit is available for every technology in the VEGA level controls range: Radar level guages, Ultrasonic Sensors, TDR, Guided Microwave radar level transmitters, Capacitance Admittance level transmitters and switches, Vibrating level switches and Pressure transmitters.
The existing stainless steel cast housing will also still be available.
The new specification is : Stainless steel (electro-polished) 316L / IP66/IP68(0.2bar)
The following general restrictions have to be taken into account:
- IP68(1bar) version is not possible.
- StEx approvals and ship approvals are not available.
For these applications the already available stainless steel versions are suitable anyway.
Posted on 03/10/07, under Information, VEGA Events · RSS · No Comments
Once again VEGA have renewed their IMC membership. As a leading level and pressure instrumentation manufacturer and companion company to the IMC, we feel it is important to support the organisation, regions as well as individual members. VEGA are always happy to participate and present to any meetings on level and pressure technologies and development, from Radar level gauges, Ultrasonic level sensors, Capacitance level and switches, Guided microwave / TDR / guded wave radar transmitters or vibronics/vibrating level switches for solids or liquids level detection. VEGA also manufacture OHMART nucleonic level, density and interface instumentation and can provide a presentation on this measurement principle technology too.
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