1.4 MILES of Wire Saved Through Innovative PLC Architecture

,,,and over 800 electrical and 40 instrument air connections!

The field wiring for our customer became very complex because they wanted verification that each of the twenty actuated valves is in the correct position.  Also, the system is pre-programmed to allow up to four additional greensand filter units through a HMI touchscreen. If the control panel with the Allen Bradley PLC is only 10 feet from the first tank, fully outfitted, this control architecture would save over 2.8 MILES of wire, 1600 electrical terminations and 80 pneumatic connections and countless hours of wiring and troubleshooting!

Fieldbus Distributed I/O Module Blocks Installed n Each Greensand Filter Unit

One of the above fieldbus distributed I/O module blocks are installed on each of the four greensand filter systems for a local brewery.  This efficient architecture:

• Requires only two cables (Ethernet and low voltage Power) from each block to the main control panel eliminating point-to-point wiring from each system to main control panel
• Eliminates over 840 sources of potential errors by mechanical contractors during field installation (800 electrical terminations and 40 pneumatic connections)
• Eliminates enclosures with a total of over 40 penetrations
• Reduces the PLC inputs and outputs by 40, thereby reducing the size of the main panel
• Is rated IP67 (Dust tight and submersible to 1 meter)
• Operates at 24 VDC

The fieldbus system we employed is the PLC distributed I/O system (remote I/O modules) that is connected to the PLC using network called fieldbus. Typical fieldbus examples: Profibus, CAN, Modbus, ControlNet, DeviceNet, Ethernet I/P. At our customer, Res-Kem used  Ethernet I/P (I/P=Industrial Protocol) fieldbus. Each block must have communication adapter that is connected to the PLC network. At our customer, the Ethernet Adapter connected to the panel Ethernet switch. In addition to I/O blocks, the vendor Res-Kem uses, has solenoid blocks that are acting like digital outputs and are attached to the I/O system. Each block (fieldbus system) is powered from 24 VDC power supply providing power for backplane.

Greensand Filters During Factory Testing Showing Location of Each Fieldbus Block

Normal practice is to add an electrical enclosure which has solenoid valves to operate pneumatic actuators and electrical terminal blocks for the limit switches and solenoid valve.  At the customer's site, each electrical enclosure needs to have point-to-point wiring to the main panel with the PLC.

Typical Solenoid Panel WITHOUT Limit Switch Terminations

More About Fieldbus:
Fieldbus is an industrial network system for real-time distributed control. It is an efficient way to connect instruments in a manufacturing plant.

From Wikipedia, "A complex automated industrial system — such as manufacturing assembly line — usually needs a distributed control system—an organized hierarchy of controller systems—to function. In this hierarchy, there is usually a Human Machine Interface (HMI) at the top, where an operator can monitor or operate the system. This is typically linked to a middle layer of programmable logic controllers (PLC) via a non-time-critical communications system (e.g. Ethernet). At the bottom of the control chain is the fieldbus that links the PLCs to the components that actually do the work, such as sensors, actuators, electric motors, console lights, switches, valves and contactors."

For Additional Information:
For technical help

Greensand filter bulletin

Customized Greensand Filter for Brewery Prepared for Shipping

With factory testing completed, Res-Kem's greensand filter with several advanced features is ready for shipment to a local brewery.  Because the water is integral to production of their beer, this expanding brewery needed features which are not typical for a greensand filter:

• Allen Bradley CompactLogix PLC with Ethernet gateway to communicate with the central plant control system.
• Expandable, in the field, from four to eight parallel greensand filter units without requiring reprogramming of the PLC.
• Multiple, user definable,  regeneration initiation options including manually initiated, differential pressure and/or totalized flow.
• Valve position feedback to insure when a valve supposed to be open or closed, the valve is in the correct position.  If incorrect, an alarm will sound and be indicated on the Panelview 1000 HMI.

Quad 48"Diameter Greensand Filter During Factory Testing

General System Information:
Four tank, continuous regeneration non-skid mounted greensand system with manual, differential pressure and/or totalized flow initiated regeneration. The system is constructed of four, 48" diameter fiberglass, non-ASME code, rated at 100 psig working pressure tanks. The system is controlled using an Allen Bradley CompactLogix PLC with an Allen Bradley Panelview Plus 1000 touchscreen HMI.  The system has Georg Fischer pneumatically actuated air-to-spring ball valves with visual and electrical valve indication.  The face piping is Schedule 80 PVC pipe and fittings.  Each vessel contains 38 cubic feet of Greensand Plus for high iron removal.  To allow for iron removal, the incoming water will be treated continuously with a chlorine dioxide generator.

Touchscreen Panelview Plus 1000 HMI for Equipment Control

For Additional Information:

Greensand filter brochure

To determine if a greensand filter will work for your company, contact us.

Condensate Polisher Shipped to New Jersey University

Last week, Res-Kem shipped a condensate polisher to a New Jersey university.  This condensate polisher will be installed as part of a new onsite power production facility at the university operated by an independent energy development company.  They will produce power for the university under a DBOM (Design, Build, Operate, Maintain) agreement. Excess power produced gets sold to the PJM.

Dual, Skid Mounted Stainless Steel Condensate Polisher with Headers

Customer	An independent energy development company specializing in the development, engineering, construction, start up, commissioning, operation, maintenance and management, as well as, ownership of Central Energy Centers, Renewable Energy projects and Combined Heat, Chilling and Power  Production Facilities.
General water treatment application	Two large 48”X60” sodium cycle condensate polisher for removal of contaminants in the return condensate and the return condensate from the steam driven chillers on-site
Savings and/or ROI the customer wants to achieve	Fuel and chemical saving related to the removal of iron and calcium from the condensate streams and ultimately the boiler feedwater
Operating conditions	250 gpm max, 150 gpm continuous operating at 180F
System configuration	Twin parallel / Alternating system
Materials of construction	Skid mounted 304 SS pressure vessels Schedule 10 welded /flanged face piping
Type of valves and actuators	Bray valves with Bray actuators
System Control	Allen Bradley PLC operates the system as alternating or parallel
System schematic	Polisher collectively handles two condensate streams – return condensate from campus and condensate from steam driven chillers
Special Features	Sample cooler mounted on skid which can sample the inlet and outlet of each vessel Inlet and outlet headers between each system on skid

Additional Information:
Listing of Condensate Polishers Built by Res-Kem
Online Catalog of Res-Kem Condensate Polishing Equipment
Condensate Polisher Technical Bulletin
Condensate Polisher Application Checklist 
For Technical Help From a Res-Kem Sales and Application Engineer

Condensate Polishing System Shipped to University in Massachusetts

A triple all stainless steel condensate polisher was shipped to a university in Cambridge, Massachusetts.  The system is designed to treat 445 gpm of condensate and is replacing an existing unit which had reached the end of its life.  This is part of a major upgrade of the steam plant including the condensate polishers, a triple dealkalizer system, which Res-Kem will provide in November, and a deaerator.

Res-Kem Triple Stainless Steel Condensate Polishing System

Here are the key features of the condensate polisher:

• For long equipment life, the system has three, 54" ASME-code tanks manufactured in 304 L stainless steel. 
• To simplify field installation, the system includes inlet, outlet, drain, backwash supply, brine and sub-surface wash headers.
• The condensate polisher incorporates Bray 31 series butterfly valves with 92 series air open/air close actuators.
• We supplied a custom designed FRP NEMA 12 panel with an Allen Bradley PLC with three solenoid boxes..
• 304L stainless steel face piping.
• Regeneration initiated via totalized flow or differential pressure.
• The flow sensors to measure the treated condensate from each of the vessels were supplied by others.
• The differential pressure switches are Orange Research 1203 DP transmitters with 4-20 mA output.
• A subsurface wash is included to increase the time between regenerations increasing total energy efficiency.
• A brine distributor for reduced salt usage
• A separate source backwash is included to increase condensate heat recovery.
• To prevent downstream damage, stainless steel resin traps are included in the treated water line.

Condensate Polishing System Being Off-Loaded at Customer's Site

Given the small space where the system is located, the standard design of the condensate polisher had to be re-engineered.  For example:

• The three pressure vessels could not be evenly placed because a vertical support beam would be in the way making each header piece unique.
• A height restriction required numerous engineering design iterations to get the system in the space allotted.
• All headers needed to be nested in a very small envelop on the front of the system.

Additional information:


Condensate Polisher Checklist Webpage Version
Condensate Polisher Checklist - PDF Version
Condensate Polisher System Brochure
Need Applications Engineer

Condensate Polisher Shipped to Arkansas

We shipped another condensate polishing system last month. This dual tank unit was shipped to a government facility in Arkansas.

Here are the key features of the polisher:

• The system has two, 36" stainless steel, ASME-code tanks mounted on a skid to treat steam condensate.
• The condensate polisher incorporates Bray 31 series butterfly valves with 93 series air open/spring return actuators.
• We use a custom designed FRP NEMA 4X panel with an Allen Bradley PLC.
• 304L stainless steel face piping.
• Regeneration initiated via totalized flow or differential pressure.
• Seametrics model IP101S flow sensors measure the treated condensate from each of the vessels.
• The differential pressure switches are Orange Research 1201 series.
• A subsurface wash is included to increase the time between regenerations increasing total energy efficiency.
• A separate source backwash is included to increase condensate heat recovery.

Additional information:
Condensate Polisher system brochure
Condensate Polisher Checklist
Need Applications Engineer

300 gpm Industrial Water Softener Shipped to a Virginia University

I nearly missed taking photos of a very nice looking quadruple tank industrial water softener that recently left our plant. As you can see, the system is being prepared for shipment and only two of the four tanks were available in this photo.

System Details:
The system has four 30" water softener vessels commonly called "mineral tanks". Each tank is rated for 75 gpm. The tanks are ASME code carbon steel tanks with a design pressure rating 100 psig.

Given the customizable standard designs we have for all of our water softening equipment and all of our industrial water treatment equipment, Res-Kem was able to accommodate the customer's request for carbon steel tanks with 304L stainless steel face piping. Bray series 21 butterfly valves with stainless steel body, 316 SS disc & stem, Teflon lined EPDM seat. Each of the automated valves were equipped with Bray series 70 electric actuators, two SPDT limit switches and a manual override handle.


The internals of the tanks use stainless steel hubs and stainless steel wedgewire laterals for long life.

The water softener system is being readied for shipment to our customer.


While our standard design uses the AquaMatic 962 controller, we offer as an option an Allen Bradley PLC. This system uses the Allen Bradley MicroLogix PLC with Panelview 600 operator interface terminal mounted in a NEMA 4X fiberglass enclosure was used to control the system.

Please contact us for further information on how to size a water softener for you requirements.