Circular Decanter Specifications





1.01 Scope of Work

A. Under this section of the specification, the Contractor shall provide all labor, materials and equipment necessary to furnish, install, test and ready for operation of ________ (__) Floating Decanter Unit(s) as shown on the contract drawings and as specified herein.

B. The system shall be furnished by a single manufacturer who is skilled and experienced in the design, manufacturing, production, sizing and testing of Floating Decanter Units for backwash water recovery. All components and materials furnished in the system shall be of high quality by well-known manufacturers.

1.02 Referenced Standards

A. ANSI - American National Standards Institute

B. ASTM - American Society for Testing and Materials

C. OSHA - Occupational Safety and Health Administration, Code of Federal Regulations, (CFR 29)

1.03 Quality Assurance

A. Each decanter unit shall be completely shop assembled to assure proper fit-up. The decanter shall then be broken down (if required ) and packaged for shipment and jobsite storage to prevent damage or corrosion.

B. The equipment seller shall be solely and fully responsible for warranty and mechanical design adequacy of all the equipment provided under this section of the specification.

C. The manufacturer shall be completely familiar with the operations of a water filtration plant, including treating filter backwash waste water. The manufacturer shall have a minimum of ten (10) years experience in design and manufacturing of Floating Decanter Units.



1.04 Submittals

A. Copies of all materials to establish compliance with the specifications shall be submitted in accordance with the provisions as outlined. Submittals shall include at least the following:

1. Complete description of all materials.

2. Drawings showing complete dimensional data of the proposed decanter design including the outline dimensions, assembly data and mounting details.

3. A complete bill of materials

4. The weight of the complete decanter assembly and each major component.

5. Description of surface preparation, shop priming and finish painting.

6. Installation, operation and maintenance information

1.05 Operation and Maintenance Data

A. Operating and maintenance instructions shall be furnished per the instructions included in the specification. The instructions shall be prepared specifically for this installation and shall include start-up data, trouble shooting guides, routine maintenance procedures, drawings, equipment lists, descriptions, etc. that are required to instruct operating personnel.

1.06 Delivery, Storage and Handling

A. All materials and equipment shall be shipped, stored, handled and installed in such a manner as to not to degrade quality, serviceability or appearance. The equipment shall be stored in a clean, dry location free from construction dust, precipitation and excess moisture.

1.07 Tools and Spare Parts

A. Furnish one set of all special tools required for the proper servicing of all equipment supplied under these specifications



2.01 General

A. The equipment herein specified is intended when installed in accordance with the drawings and the manufacturer's recommendations to permit efficient operation at the design flow of __________ GPM. Such equipment shall utilize tube settlers consisting of a number of tube-like channels at least 4.0 square inches in cross sectional area being approximately 2'-0" long and orientated at approximately 60o from the horizontal to assure that the settled particles will be purged from the tubes by force of gravity alone. The equipment shall be designed, constructed and installed in accordance with the best practice and methods, and shall operate satisfactorily when installed as shown on the drawings.

B. All parts shall be so designed and proportioned as to have liberal strength, stability and stiffness and to be especially adapted for the work to be done.

2.02 Manufacturers

A. The Floating Decanter units shall be manufactured by Enviropax, Inc., of Salt Lake City, Utah or an engineer pre-approved equal.

2.03 Materials

A. The unit shall consist of tube settler modules in a _________ ft2 area, submerged orifice collection well with an integral flotation collar, an outer baffle all mounted in an integral support frame, and guided by an exterior guide post assembly. The unit shall be designed and manufactured into an integral unit with proper allowance for flotation operation. Reclaimed water shall be discharged from the unit through the launder system into a flexible non-collapsible discharge hose provided by the reclaim manufacturer.. All fasteners required for assembly of submerged parts shall be type 316 stainless steel.

2.04 Major Components

A. The tube settlers and outer baffle shall be constructed of Acrylonitrile Butadiene Styrene (ABS) and shall be strong, rigid, resistant to chemical deterioration in an outdoor environment. The tube settler modules shall be built-up of a number of corrugated sheets with alternately placed flat sheets formed into curved sections so that all tube are full length. The individual sheets shall be solvent welded to provide strong continuous bonds and thereby form a durable homogenous structure with each tube being continuous and imperforate, eliminating mixing currents that resuspend settled solids within the tube. The corrugated sheets shall have the inclined channel configurations molded integrally therein, so that all of the tubes shall have the same angle of inclination when installed in the basin. The finished (after thermo-forming) thickness of the plastic used in the modules shall not be less than twenty (20) mils and twenty-five (25) mils for the corrugated and flat sheets respectively. The edges of the plastic shall be clean, smooth and free from burrs caused by sawing or trimming the parts to minimize the possibility of sludge buildup or growth.


B. The center collection well, flotation collar and supports shall be constructed of 1/4" minimum thick fiberglass reinforced plastic (FRP) consisting of 24 oz. woven roving and a 10 mil surface matt. The FRP structure shall have an ultimate tensile strength of not less than 16,000 psi, flexural strength of not less than 25,000, flexural modulus of not less than 838,000 psi, and a glass content of not less than 30%. The above characteristics shall be in conformance with ASTM standards D638 and D790. Reinforcing and stiffener sections shall be designed to meet the load design characteristics.


C. The discharge hose shall be a ribbed, non-collapsible, flexible hose constructed of virgin, high impact polyvinyl chloride (PVC). The hose shall be provided with factory supplied cam and grove type connectors for attachment to the reclaim discharge and outlet flanges.

D. The decanter guide and support assembly shall be constructed of 6061-T6 aluminum structural vertical and lateral members with additional stainless steel cable supports. The guide shall provide for a smooth transition through the various operating depths, and be capable of supporting the decanter unit in the low position.



3.01 Installation

A. Install in accordance with the manufacturers written instructions and as approved.

3.02 Inspection and Testing

A. After completion of installation, the equipment shall be tested by the contractor under actual operating conditions. The tests shall demonstrate that the system and individual equipment items operate properly and in all other respects fulfills its function properly and meets all requirements of the specifications.

3.03 Manufacturers Service

A. The Contractor shall have the equipment manufacturer furnish an expert factory-trained technical representative for a minimum period of one (1) full days to supervise the installation, check, the completed installation and to supervise initial operation and testing. These representatives shall also instruct the Owners personnel in the proper operation and maintenance of the equipment. No visit shall be less than five (5) hours duration.

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