PART 1 - GENERAL

         
         
         
1.1 WORK OF THIS
         SECTION
         
         
This section covers slotted
         pipe scum collection equipment to be installed in
         Sedimentation Basins. The scum collection system will
         consist of lever operated slotted skimming pipes, piping,
         and valves which will be included in each basin as shown on
         the drawings. Piping and valves are specified elsewhere. The
         scum collector manufacturer shall be the prime supplier of
         materials and equipment of the system; and provide all
         suppliers and manufactures' service as required for a
         complete and operational system.

         
         
         
1.2 GENERAL

         

         A. Scope of Supply. Equipment furnished an installed
         under this section shall be fabricated, assembled, erected,
         and placed in proper operating condition in full conformity
         with drawings, specifications, engineering data,
         instructions and recommendations furnished by the equipment
         manufacturer. All components of the scum collectors shall be
         carbon steel or 316 Stainless Steel construction.

         

         B. Manufacturer. Scum Collection equipment shall be
         as manufactured by Polytech Systems, Inc., Little Rock, CA
         Phone: 661-944-0855. Each collection system shall be
         complete with slotted pipe scum collectors including lever
         operators, pipe support brackets, and necessary
         appurtenances for a complete and functional
         installation.

         

         C. General Equipment Stipulations. The General
         Equipment Provisions shall apply to all equipment furnished
         under this section.

         

         D. Bolts and Anchor Bolts. All anchor bolts shall be
         316 stainless steel and shall be furnished by the equipment
         manufacturer. They shall be minimum 3/4" and of strength for
         the purpose intended. All anchor bolts shall be set in
         accordance with the manufacturers directions.

         

         E. Fabrication. All welded joints which will be fully
         or partially submerged shall be sealed watertight with
         continuous welds. Ferrous metal facing surfaces of bolted
         joints shall be shop painted.

         

         F. Edge Grinding. Sharp projections of cut or sheared
         edges of ferrous metal, other than stainless steel which
         will be submerged in operation shall be ground to a radius
         as required to ensure satisfactory paint adherence.

         

         G. Surface Preparation. All welds shall be thoroughly
         cleaned and ground smooth in preparation for painting. All
         iron and steel surfaces shall be solvent cleaned in
         accordance with SSPC-SPI before shop primer is applied.

         

         H. Shop Painting. All and steel surfaces shall be
         given a shop coat of the Manufacturer's standard
         rust-inhibitive primer. Requirements for additional field
         painting are covered in the painting section. (Not required
         if 304 or 316 S/S is supplied.)

         

         I. Spare Parts. The scum collection equipment for
         each basin shall be provided with the following spare
         parts:

         
         
         
Item

            Pipe collar seal

            Connecting pins

            
         
         
Spare parts shall be
         suitable packaged in accordance with the General Equipment
         Provisions with labels indicating the contents of each
         package. Spare parts shall be delivered to the Owner as
         directed.

         

         J. Structural Design. The structural design shall
         meet all applicable building and industry codes and shall be
         performed and sealed by a licensed professional
         engineer.

         

         K. Drawings and Data. Complete assembly and
         installation drawings, together with detailed specifications
         and data covering materials used and accessories forming
         part of the equipment furnished shall be submitted in
         accordance with the submittals section. Drawings shall
         indicate all dimensions as well as co-ordination aspects
         with other work.

         

         SERVICES OF THE MANUFACTURER

         

         A. Inspection, Start-up and Field Adjustment. An
         authorized service representative of the manufacturer shall
         visit the site for not less than 2 days to furnish the
         indicated services.

         

         B. Instruction of Owner's Personnel. The authorized
         service representative shall also furnish the indicated
         services for instruction of the OWNER's personnel in the
         operation and maintenance of the equipment including
         step-by-step- troubleshooting procedures with necessary test
         equipment.

         
         
         
PART 2
         PRODUCTS
         
         


         2.1 SERVICE AND INSTALLATION CONDITIONS

         

         A. All components of the slotted pipe scum
         collectors and other scum collection equipment shall be
         suitable for installation in covered primary sedimentation
         basins with a maximum concentration of hydrogen sulfide of
         200 ppm.

         

         B. The slotted pipes shall also be specifically
         designed for collection of primary scum in a Municipal
         Wastewater Treatment Plant. The slotted pipes shall be
         suitable for constant exposure to scum containing organic
         and inorganic solids, paper, rubber products, petroleum
         products, animal fats and greases, industrial solvents,
         ammonia, and detergents.

         
         
         
2.2 PERFORMANCE AND
         DESIGN REQUIREMENTS

         

         A. Each slotted pipe scum skimmer shall be
         capable of spanning the width of the sedimentation tank bay
         with maximum deflection limited to 1/16-inch (both with tank
         empty and the pipe full and vice versa) and shall allow a
         uniform flow of scum into the pipe its entire length.

         

         B. The slotted pipes shall be suitable for installation in
         primary sedimentation basins as shown on the
         drawings.
         
         
A 60 º slot
            shall be cut symmetrical about the vertical axis of
            the____ 316 series stainless steel pipe with the edges
            serving as a weir over which the skimmings flow into the
            pipe when the pipe is rotated. The edges of the slot
            shall be parallel to the longitudinal axis of the pipe.
            At regular intervals of not more than 2 '- 6 ", 2 " wide
            bands of the full pipe periphery shall be left in the
            pipe to act as stiffeners.
            
            
The revolving pipe shall
            be supported at each end in such a manner that a slight
            vertical or horizontal misalignment shall not interfere
            with the smooth operation of the pipe. The pipe shall be
            supported by and revolve in a rolled 316 series stainless
            steel collar which shall be welded to an adjustable steel
            plate. The rotating pipe shall rotate in the wall mounted
            bearings. The bearings shall be replaceable and made of
            UHMW material. The open end support shall have segments
            welded to the internal periphery of the collar to provide
            ample bearing surface for the pipe without crushing the
            seal. Hollow shaped end seals of a "D" shape
            configuration made of Nitrile or Buna N rubber shall be
            furnished.

            
            
            
A suitable watertight
            seal shall be provided between the rotating pipe and the
            wall mounted bearing. The seal shall be so constructed
            that it shall remain effective even with a slight
            misalignment of the pipe and collar. The seal shall not
            be affected by grease, mild acids, or alkalis. The seal
            shall be readily renewable without removing the pipe from
            the supporting brackets and shall not bind or impede the
            smooth action of the revolving pipe.
         
         
C. Manually Actuated
         Operator. The revolving skimming pipe shall be manually
         operated by means of a 1 1/2" stainless steel pipe lever. It
         shall be possible to rotate the pipe a minimum of 90º
         in either direction from the "off " position where the slot
         is at top dead center.
         
         
D. All parts of the
         mechanism shall be amply proportioned for all stresses that
         may occur during fabrications, erection and intermittent or
         continuous operation. Workmanship shall be of high grade in
         all respects.
         
         
E. Metal components, except
         for bronze or stainless steel, to be submerged or within one
         foot of submersible shall be shop blasted (SSPC-SP 10) and
         primed with suitable primer.

         
         
         
2.3
         MATERIALS
         
         
A. All components of the
         scum collection equipment shall be constructed of AISI type
         316 stainless steel.

         
         
         
PART 3
         -INSTALLATION
         
         


         3.1 EQUIPMENT

         

         A. Equipment shall be installed in accordance with
         manufacturer's recommendations and with reviewed
         manufacturer's shop drawings as shown on the drawings, ad as
         directed. All anchor flow into the pipe is distributed
         evenly along the entire length.

         
         
         
3.2 TESTING

         

         A. Prior to plant start-up, each of the slotted pipes
         shall be inspected for proper alignment, proper rotation
         (without binding), proper connection, and satisfactory
         performance.

         

         B. Prior to acceptance of the completed mechanisms,
         an initial performance test shall be conducted when the
         primary sedimentation tanks are filled with effluent for
         testing. Each of the slotted pipes will be tested to ensure
         even distribution of flow into the pipe and to ensure no
         leakage at the seals. Contractor shall bear costs of
         additional drain and fill of sedimentation basins required
         to correct defective work.
         
         

            

               

                  

                  
                  
Lever
                  Operated

                  Skimmers
                  
               
               

                  

                  
                  
Rotary

                  Pages
               
               

                  

                  
                  
H
                  O M E
               
            
         
          
         
         
 
         
         29233
         106th Street East • Little Rock • CA 
         93543

         PH: 661 944-0855 • FX: 661 944-0813

         Email: info@polytechcorp.us