FAQ- Frequently Asked Questions

Several key requirements need to be identified:

• Will the system be treating solids? AUTOFLOW™ systems treat liquid waste, free of solids. ThermoBatch™ systems handle liquids and solids.
• What type of heating is preferred or available; steam or electric? Either one is acceptable and there are pros and cons of each.
• What will be the total volume of waste that will need to be treated, and what is the estimated peak flow in a 24 hour period? Volume from all drains has to be considered and storage and processing tanks sized appropriately.

Two types of steam heating are allowed under National Institute of Health (NIH) Plumbing Guidelines for Effluent Treatment Systems (also referred to as Effluent Decontamination Systems).
ALLOWED- Steam Jackets External to the Tank or Direct Steam Injection
NOT ALLOWED- Steam Coils Inside the Tank
Steam coils are not in compliance with NIH standards because they may fail, contaminating the steam boiler and related piping and water conditioning systems. Because other vendors use thinner materials in steam coils than PRI's steam jackets, they are more likely to fail and need repair. There is also no way to easily determine whether the steam coil has developed a leak.

Steam Jackets have been in use not only in this industry but many others as a method to transfer heat, safely and efficiently for hundreds of years. Other vendors with limited knowledge or engineering capabilities speak of the possible failure of a Steam Jacket and encourage clients to select Steam Coils. In the past, these vendors had failures in their Steam Jackets when the Steam Jacket was also used to also cool the effluent by running chilled water into jacket. Simple logic tells you that once metal is hot you do not hit the metal with cold water or you will see thermal shock and a rapid reduction in temperature, causing significant stress on the metal. Other methods of cooling should be used such as a sparger or the use of heat exchangers.

Steam Jackets used to transfer heat have a wall thickness much greater than a coil and will provide a longer life span for the heating system.

There are no issues with flush mounted ball valves. Balls valves are an industry standard and have proved themselves reliable in all of our systems, including systems that have been in continuous operation for over 10 years. Proper engineering and proper selection of all devices is critical to ensure the best system is provided.

A vendor has been raising issues with flush mounted ball valves and has been encouraging facilities to purchase Effluent Treatment Systems with "dead legs". The pharmaceutical industry does not allow "dead legs" in any major system and in the case of an Effluent Decontamination System, one would expect the same. A "dead leg" is a potential problem for biological sterilization. Not only does this create the potential for pathogens to survive, it also creates the need for an additional heating and monitoring system, that in-turn, is an additional point of failure in the system. With a "dead leg" and a horizontal ball valve in place, you are not increasing the life of the ball valve as the valve is equally exposed to the same operation; open and closed. It is simply in a different position.

No. A basket or strainer to collect solids is a design mistake. PRI's system is designed to treat liquids containing solids and will treat any solid that will flow through the waste lines. All output drains and valves in the system will handle any solids that the input piping to the system will allow to pass.

A basket or strainer in the cook tank creates the issue of trapped solids and how they are to be removed from the tank. Protocol in most labs requires the piping and vessels be decontaminated before entry; with decontamination meaning more thorough process than just running the cook tank through a cycle.

To clean a basket in the vessel, a man way will have to be opened and the solids removed manually from the tank.

There is no way to determine that from outside the vessel and doing it as routine maintenance on a regular basis may not be adequate due to the unpredictability of the effluent composition flowing to the tank.

Vendors using collection baskets have "dead legs" in their system and steam coils in the tanks and are trying to protect their dead legs from being clogged and the coils from building up thick layers of cooked solids on the metal, reducing the heat transfer capability of the system.

What is the difference between hydraulic opening/closing of a lid and hydraulic latching of a lid?

Lids on a caustic digestor are very heavy and because of the pressures in the vessel, have to be securely closed and latched before the process starts. On small units this can be accomplished by an operator with minimal problems by the use of spring assist or with a small hydraulic cylinder to open and close the lid. For operator safety, lids on large units must be opened and closed with some type of mechanical assistance. A hydraulic cylinder is the most common assistance provided. Operator controls for this operation must be located away from the vessel so there is no chance the operator can be harmed when the lid closes. Barriers should be considered to keep others away from the vessel when opening and closing.

Many large digesters have been provided by some firms that require manual latches to be tightened before the process can start. While the use of manual latches saves money at the initial purchase, they can have a considerable cost over the lifetime of the equipment. Because of the high number of latches required, closing and tightening these latches can be very time consuming if proper tightening procedures are used. Latches should be tightened in a specific sequence and to a specific torque in at least a two step process to insure uniform tightening and no damage to the gaskets or load bearing surfaces. Improper tightening procedures can lead to gasket damage and warped lids that will not tighten properly and retain the design pressure.

A hydraulic latching mechanism creates uniform pressure on the lid and makes sure a tight fit is achieved without a chance of warping the lid. Proximity switches confirm the travel of the hydraulic cylinders and along with the pressure sensors assure the lid is properly latched before the cycle is started.
While the initial cost of the hydraulic latching mechanism may be higher, the resulting savings in man hours and cost avoidance of replacing gaskets and possible lid damage is significant.

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How are systems shipped to the customer?

Responsibility for freight is a negotiated item and regardless of whose responsibility it is, it needs to be done properly to be sure the equipment arrives in good condition.
We suggest that almost any system be shipped on a dedicated truck to eliminate freight handling at terminals. We have found that damage occurs at that point and loads are often not well secured when put into the truck. If a unit is very small and has to go LTL, PRI should be notified and extra crating can be built around the unit to help prevent damage during shipment.
We also suggest that systems be placed on trailers that can provide an air ride. This will cushion some of the shock from rough roads and minimize potential damage. There is an extra charge for this type of trailer so be sure to specify it when getting freight quotes.

PRI has found that loads shipped on flat bed trucks need to be tarped. If loads are not tarped, they are subject whatever weather conditions that occur in transit and the wind swirling through the load can cause damage to insulation and other components. Tarping is also an extra charge but well worth the money.

PRI takes photos of the loads as they go on the trailer to document crating and condition when shipped. These photos will be emailed to you after the truck leaves so you can be prepared for the unloading process and in the event a freight claim needs to be filed.

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What are move-in issues?

Putting a new piece of equipment into a facility under construction is generally not a problem if walls and roofs are not in place. Putting a new system into an existing facility may present challenges that need to be addressed early in the project.

Access to the area where the equipment is to be installed has to be considered early in the project when the capacity and configuration of the system is being considered. Tank shape and orientation can often be changed and system components can be designed to be disassembled if they are too big to be easily moved. If sensors, gages and other components have to be removed before move in, it will be better if they are removed at the factory before shipment.

If tanks can't be moved in their normal installation orientation, consideration must be given for non-standard placement of lifting lugs and other methods of handling the equipment.

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What is an FAT and should the customer be there when it is performed?

The Factory Acceptance Test is performed on an equipment system at the manufacturer's location and is generally the last step in the manufacturing process. Is it performed to test all the operating functions of the system and make sure that unit will operate properly in both normal operating conditions and when there is an upset in the system. All the steps in the testing process are documented and retained by interested parties.

The customer may elect to witness the FAT or choose to request written documentation that the test was performed. Being on site to witness the FAT is an excellent way to learn the function of all the system components and minimize startup concerns in the field. Depending on the size and complexity of the system, a FAT may take three days to multiple weeks.
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What is the difference between remote monitoring of a system and remote operation?

Generally a control panel for a system is mounted in the vicinity of the system to allow operators to monitor and control the process. Mounting the panel near the system reduces the cost of installation and makes troubleshooting the system easier.

When systems are designed to run automatically and an operator is seldom near the system, there may be a desire to remotely monitor the operation of the system. Monitoring the system is considered to be a passive operation where an operator can confirm proper operation of the system but not be able to initiate or terminate a process or change set points. Monitoring may be done on a computer screen or simply by indicator lights showing the status of the operation.

If an operator wishes to be able to change set points, initiate a process, acknowledge alarms and perform other interactive functions with the system, remote operation will have to be provided. There are a number of different ways to do this, ranging from an HMI screen in parallel with the one on the control panel to having a complete computer system that will allow programming changes in the software.

Your exact needs should be discussed with your sales engineer so the proper interface can be supplied with your system.

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Why are treatment tanks passivated?

While stainless steel tanks have a high degree corrosion resistance, it is hard to predict what chemicals will be used in a lab and introduced into treatment tanks. When you add the uncertainty of chemical volume and how different chemicals may react with one another, it is prudent to consider taking steps to minimize the potential for corrosion.

Passivation cleans the surface and creates a non-reactive surface film that inhibits further corrosion. It is done before the tank and piping is put into service and generally does not have to be done again during the life of the system.