TowerSystem  Filtration  Systems:  STS SERIES                     Revised 2-21-01

Sample Specifications

Filtration Type & Performance
The removal of specific unwanted contaminants from a pumped/pressurized fluid flow system shall be accomplished with a sand media filtration package.  Performance shall be prescribed for matter as fine as 5 microns, based on the specific sand media employed. 

Filtration System Design & Function
A system-matched pump directs the fluid through a 3-way valve into the top inlet of a sand media filter tank.  Flow is evenly dispersed across the sand media bed via a dispersion plate, allowing the fluid to pass through the sand media and capturing the contaminants on the surface and upper layer of the sand media.  Fluid flow continues through the sand media to the filter tank's integral underdrain, directing water to the filter system's outlet.

The underdrain shall feature a full-size manifold with complete coverage laterals to ensure that filter flow and backwash flow are uniform across and throughout the sand media bed.

Backwashing/Contaminant Removal
The accumulation of contaminants on the sand media surface shall be monitored via pressure differential from inlet to outlet.  At a prescribed pressure differential or a given period of time or operator discretion, the filter system shall backwash the captured contaminants to desired waste.  This function shall be a) automatically controlled via a pressure differential gauge and clock timer, or b) manual, monitored and initiated by an operator.

The 3-way valve at the inlet shall be actuated hydraulically by solenoid or manual valve to interrupt system flow and provide a backwash discharge outlet.  Backwash flow shall come from either a) the system flow, redirected through filter tank's outlet and underdrain, or b) a separate flow source, such as city water, directed through the filter tank's outlet and underdrain.  

Backwash flow and pressure shall be sufficient to fluidize the sand media bed and cause the surface contaminants to rise in suspension and discharge via the 3-way valve to desired waste.  

Upon completion of the backwashing cycle, the inlet's 3-way valve shall again return to its operating position, allowing system flow to enter the filter tank and simultaneously interrupting backwash discharge.  This allows the sand media bed to again settle, forming the filtration surface for further contaminant removal.

continued on reverse	
Filter System Details
A. Inlet shall be female threaded, NPT, size: __________
B. Outlet shall be grooved-end pipe connection, size: ________
C. Backwash discharge outlet shall be grooved-end pipe connection, size: __________
D. Backwash supply line (if not using redirected system flow) shall be grooved-end pipe connection, size: ___________
E. The filter system shall operate at a flow rate of: __________
F. Pressure loss shall not exceed 12 psi (0.8 bar) 

Filter System Construction
Filter tank -  Stainless steel, 304L with minimum wall thickness of 14 gauge (domes) and 14 gauge (walls); top inspection port shall feature an epoxy-coated, cast-iron bolt-on cover; lower clean-out port is female NPT coupling with plastic (PVC) plug.

Underdrain - Schedule 40 PVC header; PVC internally v-slotted well screen (.010 slot opening size) with a minimum collapse strength of 135 psi (9.3 bar); Durability shall be warranted for 15 years.

Pump - End-suction, single stage; TEFC motor, cast iron housing; iron impeller; bronze shaft sleeve; BUNA-N mechanical shaft seal.

Backwash valves - Cast-iron body; hydraulically-actuated, epoxy-coated internal water-contact surfaces; stainless steel shaft and either stainless steel or PVC guide bushing; stainless steel disc with vulcanized BUNA-N rubber to seal the backwash port; rubber boot shall be field serviceable without removing the valve from the filter system.  Fail-safe to prevent system fluid loss to backwash waste in the event of a power failure.

Controller - IEC starter with overload module; HOA selector switch; NEMA-4X 
enclosure; re-set/disconnect/trip switch; 120 volt, single phase control voltage; manual backwash switch; pressure differential switch; backwash cycle timer; 24-hour backwash clock.

Piping - Galvanized pipe with grooved couplings.

Filter media - Uniformly graded silica sand media; options:
* 10 microns at 95% efficiency
* 5 microns at 90% efficiency

Skid - Stainless steel, 3/16-inch minimum thickness.

Filtration System Source & Identification
The filter system shall be manufactured by LAKOS Filtration Systems, a division of Claude Laval Corportation in Fresno, California USA.  Specific model designation is: __________________