STA-RITE U-3 - User Manual

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STA-RITE U-3 SKIMMER

INSTALLATION, OPERATION & PARTS

Sta-Rite Pool/Spa Group

293 Wright Street, Delavan, WI 53115

International: 262-728-5551, FAX: 262-728-7550

www.starite.com

Union City, TN • Delavan, WI • Mississauga, ON

Blocking pump suction can cause pressure

surges and water hammer, which can damage pump or piping

and may cause flooding.

OPERATION

All Models:

Pump suction pulls water through skimmer. Water flow into

skimmer carries floating leaves, bugs, etc., into skimmer where

they are trapped in skimmer basket. (Dust, body oils, etc., go on

through to be removed by pool filter.) Floating weir in skimmer

opening enhances surface flow and skimming action. Model

Series 1403, 2403, 1404 and 2404 are NSF listed.

Water level: Keep pool, spa, or hot tub water level at least 1-1/2

to 2" above bottom of skimmer opening for proper operation.

Float Valve: Float valve protects pump from loss of prime if

skimmer clogs or flow through skimmer is restricted. Trimmer

valve plate on bottom of float valve balances flow between

skimmer and main drains.

Flow adjustment: Balance flow between skimmer and main drain.

A. Skimmers without float: Adjust shut-off valves in pump suc-

tion line from skimmer and pool main drain line. (See

Figure 1, below.)

B. Skimmers with float: If skimmer is equipped with float

valve, adjust trimmer plate on bottom of float. To reach

trimmer plate, remove cover, basket, and float valve (See

Figure 2, below). Swing trimmer plate to one side to

increase trimmer port size (more flow through skimmer, less

flow through main drains); reduce port size for less flow

through skimmer and more flow through main drains.

Sweeping pool: For installation without equalizer line, hold

weir up to starve skimmer of water and close float valve. This

directs all flow through main drains. To return to normal skim-

ming operation, turn pump off 10-15 seconds, allowing skim-

mer to fill and float valve to return to open position. Skimmer

will now operate normally as long as pool water level is high

enough to allow normal flow over weir.

Hazardous Suction.

Risk of hair or body

entrapment, drowning or

disembowelment.

Wall fitting on equalizer line must

be non-entrapping of hair or body

at flow rates upto 55 GPM.

NOTE: Skimmer is not equivalent

to a main drain. All pools, spas, and hot tubs must have at

least two main drains besides skimmer(s).

Save these instructions. Carefully read and follow all safety instructions in this manual.

Flow

Through

Skimmer

To Pump

Suction

Float

Valve

Open

Check

Valve

Shut

Equalizer

Line

1023 0694

From

Equalizer

Outlet

To Pump

Suction

Float

Valve

Shut

Check

Valve

Open

1022 0694

No Flow

Over

Weir

To Pump

Suction

Remove Check

Valve; Plug

Equalizer (or

Main Drain)

Port

Equalizer

Line

1021 0694

Vacuum

Plate

Pool Vacuum

Hose

Figure 1: Normal operation: float

valve open, check valve shut.

Figure 2: Equalizer operation; float

valve shut, check valve open.

Figure 3: Vacuuming pool; float and

check valves removed, equalizer (check

valve) port plugged.

Typical Public Pool Skimmer Installation with Equalizer Line Installed

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Summary

Skimmer Operation and Safety

Water Level

Maintain pool, spa, or hot tub water level at least 1-1/2 to 2" above skimmer opening for proper operation.

Float Valve

Protects pump from loss of prime if skimmer clogs or flow is restricted. Balances flow with main drains.

Flow Adjustment

Skimmers Without Float

Adjust shut-off valves in pump suction line from skimmer and pool main drain line.

Skimmers With Float

Adjust trimmer plate on bottom of float valve to balance flow between skimmer and main drains.

Sweeping Pool

Directs all flow through main drains when skimmer is starved of water by holding weir up.

Vacuuming Pool

Procedure

Remove components, plug equalizer, attach vacuum plate, fill hose, and connect to plate.

Public Pool Models

Check Valve

Prevents flow through equalizer line when closed; opens to allow flow from main drain if pump is starved.

Equalizer Bypass

Emergency bypass to prevent pump damage when water level is low or skimmer is blocked.

Maintenance

Weir and Strainer Basket

Check weir for free operation and empty strainer basket for accumulated debris regularly.

Float Valve and Check Valve

Periodically check float valve for free operation and inspect check valve for wear or deterioration.

Water Level and Winterizing

Maintain water level and drain pool below skimmer inlet for winterizing.

Repair Parts List

Part Identification

Lists key components of the skimmer with corresponding part numbers for public and residential models.

Suction Pipe Sizing Chart

Provides guidance on pipe sizing based on pool surface area and skimmer rated flow capacity.

Skimmer Layout and Suction Line Sizing

General Requirements

Requires at least two main drains and specifies suction line velocity and sizing based on total skimmers.

Installation

Details concrete surround, line connections, testing, and use of ABS/PVC solvent cement.

Summary

Skimmer Operation and Safety

Water Level

Maintain pool, spa, or hot tub water level at least 1-1/2 to 2" above skimmer opening for proper operation.

Float Valve

Protects pump from loss of prime if skimmer clogs or flow is restricted. Balances flow with main drains.

Flow Adjustment

Skimmers Without Float

Adjust shut-off valves in pump suction line from skimmer and pool main drain line.

Skimmers With Float

Adjust trimmer plate on bottom of float valve to balance flow between skimmer and main drains.

Sweeping Pool

Directs all flow through main drains when skimmer is starved of water by holding weir up.

Vacuuming Pool

Procedure

Remove components, plug equalizer, attach vacuum plate, fill hose, and connect to plate.

Public Pool Models

Check Valve

Prevents flow through equalizer line when closed; opens to allow flow from main drain if pump is starved.

Equalizer Bypass

Emergency bypass to prevent pump damage when water level is low or skimmer is blocked.

Maintenance

Weir and Strainer Basket

Check weir for free operation and empty strainer basket for accumulated debris regularly.

Float Valve and Check Valve

Periodically check float valve for free operation and inspect check valve for wear or deterioration.

Water Level and Winterizing

Maintain water level and drain pool below skimmer inlet for winterizing.

Repair Parts List

Part Identification

Lists key components of the skimmer with corresponding part numbers for public and residential models.

Suction Pipe Sizing Chart

Provides guidance on pipe sizing based on pool surface area and skimmer rated flow capacity.

Skimmer Layout and Suction Line Sizing

General Requirements

Requires at least two main drains and specifies suction line velocity and sizing based on total skimmers.

Installation

Details concrete surround, line connections, testing, and use of ABS/PVC solvent cement.

The Sta-Rite U-3 Skimmer is a device designed for pool, spa, and hot tub water circulation and surface cleaning. It functions by pulling water from the surface, trapping floating debris in a basket, and directing the water to the pool filter for further purification.

Function Description:

The primary function of the U-3 Skimmer is to remove floating leaves, bugs, and other debris from the water surface, preventing them from sinking and making the pool harder to clean. It also helps in removing body oils and dust, which are then captured by the pool filter. The skimmer utilizes a floating weir in its opening to enhance surface flow and skimming action, ensuring efficient debris collection.

The skimmer can be installed with or without an equalizer line, which is a safety feature designed to prevent the pump from losing prime if the skimmer clogs or the water level drops too low. In installations with an equalizer line, a check valve is threaded into the equalizer inlet port. When the skimmer's float valve drops due to restricted flow, the check valve opens, allowing the pump to draw water from the main drain/equalizer line, thus preventing pump starvation.

For installations without an equalizer line, the skimmer relies on main drains to provide water to the pump if the skimmer's flow is restricted. In these setups, shut-off valves in the pump suction line from both the skimmer and the main drain are used to balance flow.

Important Technical Specifications:

Material: ABS plastic.
Manifold Connections: 1-1/2 or 2" threaded, or 1-1/2" slip.
Equalizer Line Wall Fitting: Must be non-entrapping of hair or body at flow rates up to 55 GPM and conform to ANSI/ASME A112.19.8M-1987 (Section 8.8.2). An 8011-Series non-entrapping suction fitting is recommended for the equalizer line.
Skimmer Rated Flow (GPM): Varies based on pool surface area and number of skimmers. For example, a 600 sq. ft. pool requires one skimmer with a 30-50 GPM flow, while a 6,000 sq. ft. pool requires twelve skimmers with a 30-50 GPM flow each.
Pipe Sizing: Suction line sizes are based on a water velocity of less than seven feet per second. Chart I in the manual provides guidance for suction pipe sizing based on pool surface area and skimmer flow capacity.
Installation Requirements:
- At least two main drains, at least three feet apart, are required in addition to any skimmers.
- One skimmer per 500 square feet of pool surface area.
- Skimmer must be surrounded by at least 4" of structural concrete in a monolithic pour.
- Top cover frame has 1" vertical height adjustment.
- Minimum water level: 1-1/2 to 2" above the bottom of the skimmer opening.
NSF Listing: Model Series 1403, 2403, 1404, and 2404 are NSF listed.

Usage Features:

Flow Adjustment:
- Skimmers without float: Flow is balanced by adjusting shut-off valves in the pump suction line from the skimmer and main drain.
- Skimmers with float: Flow is balanced by adjusting a trimmer plate on the bottom of the float valve. The trimmer plate can be swung to one side to increase (more flow through skimmer) or reduce (less flow through skimmer) the port size.
Float Valve: This feature protects the pump from losing prime if the skimmer clogs or flow is restricted. The trimmer valve plate on the bottom of the float valve also helps balance flow between the skimmer and main drains.
Equalizer Operation: In public pool models with an equalizer line, if the flow over the weir is restricted, the float valve closes, diverting pump suction to the equalizer (or main drain) line, preventing pump prime loss. The check valve in the equalizer line opens to allow this flow.
Sweeping Pool: For installations without an equalizer line, the weir can be held up to starve the skimmer of water, and the float valve closed (if applicable), directing all flow through the main drains for vacuuming.
Vacuuming Pool: The skimmer can be used for vacuuming by removing the cover, basket, and float valve (if present), plugging the equalizer inlet (if applicable), and placing a vacuum plate on top of the basket. The vacuum hose is then attached to the vacuum plate.

Maintenance Features:

Weir: Periodically check for free operation and replace if damaged or worn.
Strainer Basket: Check every few days for accumulated debris. Empty as required and reset the float valve if it has closed.
Float Valve: Periodically check that it operates freely and is not waterlogged. Tighten the trimmer plate pivot screw to maintain desired flow balance.
Check Valve (Public Pool Models): Inspect for wear or deterioration. Ensure the screw in the check valve body is tight. Replace the check valve if flow is detected through the equalizer with the float valve open. The check valve is factory pre-set and not adjustable.
Equalizer (Wall) Fittings: Periodically check that wall fittings are correctly installed and that covers are tight to prevent entrapment.
Water Level: Maintain water level at 1-1/2 to 2" above the bottom of the skimmer opening. Adjust the trimmer plate if necessary and ensure the set screw is tight.
Winterizing: Drain the pool below the skimmer inlet. Remove the cover, basket, and float. Plug both bottom ports with standard 1-1/2 or 2" pipe plugs. Cover the skimmer to prevent rainwater or snow accumulation.
Skimmer Grate/Cover: Periodically check the skimmer cover for cracks, chips, or deterioration of plastic. Replace if any damage or deterioration is found, as prolonged use can lead to reduced strength and create a falling and tripping hazard. The cover must fit flush with the pool, spa, or hot tub deck level.