Mer-Made Filter, Inc. · Pumps, Circulation and Flow Control · Surge, balance and collector tanks
Fiberglass surge and balance tanks
Individually engineered fiberglass surge and balance tanks, vertical or horizontal, with main drain float valve.
Overview
Surge tanks are generally required on gutter pools to provide storage (surge capacity) for water displaced by swimmers. Mer-Made's preferred arrangement holds back the main drain with a float-ball-controlled modulating valve so gutter water flows to the surge tank instead of backing up in the pool. The manufacturer defines surge capacity as the tank volume above the centerline of the main drain connection and notes that a common health department requirement is one gallon per square foot of pool surface area. Balance or collector tanks are smaller tanks that accept main drain and gutter water with an outlet to pump suction and are usually not large enough to meet surge capacity codes.
Tanks are contact-molded fiberglass using corrosion-resistant isophthalic polyester resin with a 100 mil corrosion liner and heavy-duty fiberglass fabric reinforcement, built to ASTM D-4097 and NBS PS15-69, with UV inhibitors on the exterior. Fiberglass flanged fittings are located as required with ANSI 150 lb drilling patterns; the main drain is supplied with a Mer-Made modulating float valve. Vertical tanks have the manway on the top dome by default (side manway optional); horizontal tanks have a side manway with a flanged, gasketed clear acrylic cover for observing float valve operation, and are supported on two bonded saddles giving 6 in. floor clearance. Every tank is hydrostatically tested before shipment.
Tanks are designed for use below pool deck level in fully flooded service and must be vented above pool water level with a vent no less than one pipe size smaller than the pump suction. The standard horizontal tank must not be buried. Options include multi-section tanks with bolted body flanges, internal piping and elbows, an internal vortex breaker, sight glass or probe chamber, a water level controller system, stacked configurations and equalization fittings between multiple tanks. Capacities and dimensions are per project; the horizontal chart is based on a 5 ft shell length with custom lengths available.
Is this a fit for your facility?
Usually a fit when
- Gutter (perimeter overflow) pools that must meet a health-department surge capacity requirement.
- New construction or renovations where the tank sits below deck level in an equipment room or pit.
- Projects needing a custom-sized or segmented tank to pass through existing doorways or fit restricted spaces.
Look elsewhere when
- Direct burial: the manufacturer states the standard horizontal tank must not be used for buried service.
- Installations that cannot provide a vent above pool water level sized per the manufacturer's requirement.
Ideal facilities and conditions: Surge storage for gutter pools; Balance/collector tank between main drain, gutters and pump suction; Stacked or multiple-tank surge systems with equalization fittings; Custom open-top rectangular surge tanks.
Problems it addresses
Key capabilities and benefits
Capabilities
- Contact-molded fiberglass with corrosion-resistant isophthalic polyester resin and 100 mil corrosion liner; built to ASTM D-4097 and NBS PS15-69.
- Vertical and horizontal closed-top tanks, custom open-top rectangular tanks, and segmented tanks with bolted body flanges.
- Fiberglass flanged fittings with ANSI 150 lb drilling patterns, located as required by site conditions.
- Main drain supplied with a Mer-Made modulating float valve; horizontal tanks have a clear acrylic side manway cover to observe it.
- Each tank individually engineered and hydrostatically tested at the factory before shipment.
- Options: internal vortex breaker, internal piping and elbows, sight glass or probe chamber, water level controller system.
Available models and configurations
Technical specifications
| Resin | Corrosion resistant isophthalic polyesterSource: https://mermade.com/wp-content/uploads/sites/4/2022/03/mermade-filter-surge-balance-tank-brochure-dimensional-capacity-and-chart-data.pdf |
|---|---|
| Construction | Contact molded, 100 mil corrosion liner with heavy duty fiberglass fabric reinforcement layersSource: https://mermade.com/wp-content/uploads/sites/4/2022/03/mermade-filter-surge-balance-tank-brochure-dimensional-capacity-and-chart-data.pdf |
| Construction standards | ASTM D-4097 and NBS PS15-69Source: https://mermade.com/wp-content/uploads/sites/4/2022/03/mermade-filter-surge-balance-tank-brochure-dimensional-capacity-and-chart-data.pdf |
| Exterior | Protected with ultraviolet light inhibitorsSource: https://mermade.com/wp-content/uploads/sites/4/2022/03/mermade-filter-surge-balance-tank-brochure-dimensional-capacity-and-chart-data.pdf |
| Fittings | Fiberglass flanged fittings with ANSI 150 lb standard drilling patternsSource: https://mermade.com/wp-content/uploads/sites/4/2022/03/mermade-filter-surge-balance-tank-brochure-dimensional-capacity-and-chart-data.pdf |
| Main drain | Provided with Mer-Made modulating float valveSource: https://mermade.com/wp-content/uploads/sites/4/2022/03/mermade-filter-surge-balance-tank-brochure-dimensional-capacity-and-chart-data.pdf |
| Testing | Hydrostatically tested at factory prior to shipmentSource: https://mermade.com/wp-content/uploads/sites/4/2022/03/mermade-filter-surge-balance-tank-brochure-dimensional-capacity-and-chart-data.pdf |
| Venting | Must be vented above pool water level; vent no less than one pipe size smaller than pump suction, unobstructedSource: https://mermade.com/wp-content/uploads/sites/4/2022/03/mermade-filter-surge-balance-tank-brochure-dimensional-capacity-and-chart-data.pdf |
| Surge capacity definition | Volume of the tank above the centerline of the main drain connection; common code requirement one gallon per sq. ft. of pool surfaceSource: https://mermade.com/wp-content/uploads/sites/4/2022/03/mermade-filter-surge-balance-tank-brochure-dimensional-capacity-and-chart-data.pdf |
| Tank styles | Vertical and horizontal closed top; custom open top rectangular; segmented with body flangesSource: https://mermade.com/wp-content/uploads/sites/4/2022/03/mermade-filter-surge-balance-tank-brochure-dimensional-capacity-and-chart-data.pdf |
Specifications are summarized from manufacturer literature and depend on configuration. Confirm current values with FreyTech before design.
Installation requirements and retrofit considerations
Prerequisites
- Installation below pool deck level with the tank in fully flooded service.
- A vent to a point above pool water level, no less than one pipe size smaller than the pump suction and never reduced or obstructed.
- Fitting locations, manway and drain orientation specified at order, since surge capacity depends on the main drain elevation.
Retrofit and replacement notes
- Tanks can be built in multiple sections with bolted body flanges to accommodate installation restrictions.
- Fittings may be placed on top, on domes or on the side wall as site conditions require; multiple tanks can be joined with equalization fittings or stacked.
Integration with other equipment
No equipment integrations are documented for this product. Coordination happens through the design team.
FreyTech's role: design, installation, commissioning, training, support
Project services
- Evaluation of fit for your facility
- Supply, lead time and pricing confirmed on request
- Installation and support coordination where the product calls for it
Ongoing service and support
- Parts, consumables and warranty coordination through FreyTech
Brochures, manuals, warranties and specifications
- Product pageSurge and Balance Tanks (product page) (opens manufacturer site)Web · Manufacturer-hosted
- BrochureSurge and balance tank brochure with dimensional and capacity chart data (opens manufacturer site)PDF · Manufacturer-hosted
- Specification sheetVertical fiberglass surge tank drawing T-14396 (opens manufacturer site)PDF · Manufacturer-hosted
- Specification sheetHorizontal fiberglass surge tank drawing T-14395 (opens manufacturer site)PDF · Manufacturer-hosted
All resources for Fiberglass surge and balance tanks · Request documents
Fiberglass surge and balance tanks: frequently asked questions
What is the difference between a surge tank and a balance tank?
Per Mer-Made, a surge tank provides storage capacity above the main drain centerline for water displaced by swimmers, sized to code (commonly one gallon per sq. ft. of pool surface). Balance or collector tanks are smaller tanks that accept main drain and gutter water with an outlet to pump suction and usually do not meet surge capacity requirements.
Can the tank be buried?
The manufacturer states the standard horizontal tank must not be used for buried service; tanks are designed for installation below pool deck level in an equipment space.
Next step
Is Fiberglass surge and balance tanks right for your facility?
Send us your pool volumes, current equipment, and what is not working. A specialist will review fit honestly and recommend next steps.
Serving commercial aquatic facilities across New York State.