FRP Pressure Vessels – 2.5″ NPSM Series for Water Treatment
High-performance FRP pressure vessel featuring a standard 2.5″ NPSM threaded opening. Designed for residential and light commercial water treatment, this tank is universally compatible with Runxin, Fleck, and Clack control valves, making it the ideal housing for water softeners, carbon filters, and RO pre-treatment systems.
Product Description
The Backbone of Efficient Water Filtration Systems.
The Stark 2.5″ NPSM Series is our most versatile line of composite fiberglass pressure vessels. Unlike traditional steel tanks that are prone to rust and heavy to handle, our composite vessels feature a seamless high-density polyethylene (HDPE) inner liner wound with continuous fiberglass strands and sealed with high-grade epoxy resin.
This advanced construction ensures 100% corrosion-free performance and zero contamination, making it perfect for drinking water applications and critical RO pre-treatment stages.
Technical Note:
Our tanks undergo rigorous burst pressure and fatigue testing. For detailed structural stress analysis, raw material composition, or specific manufacturing protocols, please reference the official technical data at our specialized manufacturing division:
Stark Tank Manufacturing – 2.5″ NPSM Series Specs
Product Parameter
Use the chart below to select the correct vessel size based on your required resin volume or flow rate.
| Model | Volume Capacity | Dimensions (Dia x H) | Flow Rate (m³/h) | B2B Quote | ||
|---|---|---|---|---|---|---|
| Type | US Gal | Liters | Inch | mm | Reference | Action |
| STK-713 | 1.6 | 6 | 7″ x 13″ | Ø180 x 335 | 0.3-0.7 | Inquiry |
| STK-717 | 2.4 | 9 | 7″ x 17″ | Ø180 x 430 | 0.3-0.7 | Inquiry |
| STK-735 | 5.3 | 20 | 7″ x 35″ | Ø180 x 905 | 0.3-0.7 | Inquiry |
| STK-817 | 2.9 | 11 | 8″ x 17″ | Ø205 x 445 | 0.3-0.7 | Inquiry |
| STK-835 | 6.3 | 24 | 8″ x 35″ | Ø205 x 905 | 0.3-0.7 | Inquiry |
| STK-844 | 8.7 | 33 | 8″ x 44″ | Ø205 x 1130 | 0.3-0.7 | Inquiry |
| STK-935 | 8.7 | 33 | 9″ x 35″ | Ø230 x 905 | 0.5-1.2 | Inquiry |
| STK-942 | 10.3 | 39 | 9″ x 42″ | Ø230 x 1085 | 0.5-1.2 | Inquiry |
| STK-948 | 11.9 | 45 | 9″ x 48″ | Ø230 x 1230 | 0.5-1.2 | Inquiry |
| STK-1017 | 4.8 | 18 | 10″ x 17″ | Ø255 x 445 | 0.8-1.4 | Inquiry |
| STK-1035 | 10.3 | 39 | 10″ x 35″ | Ø255 x 905 | 0.8-1.4 | Inquiry |
| STK-1044 | 12.9 | 49 | 10″ x 44″ | Ø255 x 1130 | 0.8-1.4 | Inquiry |
| STK-1054 | 16.4 | 62 | 10″ x 54″ | Ø255 x 1390 | 0.8-1.4 | Inquiry |
| STK-1252 | 22.5 | 85 | 12″ x 52″ | Ø300 x 1340 | 0.8-1.5 | Inquiry |
| STK-1265 | 28.0 | 106 | 12″ x 65″ | Ø300 x 1650 | 0.8-1.5 | Inquiry |
| STK-1354 | 27.5 | 104 | 13″ x 54″ | Ø330 x 1400 | 1.2-2.3 | Inquiry |
| STK-1665 | 49.7 | 188 | 16″ x 65″ | Ø400 x 1670 | 1.2-2.3 | Inquiry |
*Flow rates are for reference only. Please consult our engineers for specific system design parameters.
Applicable Industry
- Water Softening Systems:
Ideal housing for cation exchange resin to remove calcium and magnesium hardness in residential and industrial boiler feed water. - Activated Carbon Filtration:
Used for de-chlorination, organics removal, and taste/odor improvement in municipal water supply lines. - RO Pre-Treatment:
Acts as the primary sand/multimedia filter to protect sensitive Reverse Osmosis membranes from sediment and particulate fouling.
Advantage One
Corrosion-Resistant Composite Construction
Stark FRP vessels are engineered to outlast traditional steel tanks in aggressive water environments. The inner shell is molded from seamless, food-grade High-Density Polyethylene (HDPE), ensuring that water never touches metal. This guarantees zero rust and no heavy metal leaching. The outer shell is reinforced with continuous strands of fiberglass embedded in high-performance epoxy resin, providing a pressure rating of 150 PSI (10.5 Bar) while being 60% lighter than steel equivalents.Advantage TWO
Universal Compatibility & Easy Maintenance
Designed with the system integrator in mind, the 2.5″ NPSM threaded top opening is manufactured with precision tolerances to ensure a leak-free seal with all major control valve brands, including Runxin, Fleck, Clack, and Autotrol. The lightweight composite structure simplifies transport and installation, allowing a single technician to position the tank and load media (Resin, Carbon, or Sand) without the need for heavy lifting equipment.Related Products
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FAQ
Q1: How long does the reverse osmosis system last?
The lifespan of a reverse osmosis system depends on water quality and maintenance. Typically, the membrane lasts 2–3 years, while the system itself can last over 10 years with proper care.
Q2: Can the system be customized based on different water conditions?
Yes, all our systems are fully customizable. We analyze your water report and application needs before providing tailored solutions.
Q3: What standards does STARK equipment comply with?
Our products comply with CE, ISO 9001, and can be designed to meet specific regional regulations or industry standards upon request.
Q4: What is the delivery time for STARK RO systems?
Standard systems are shipped within 7–15 days. For customized orders, lead time may extend to 20–25 days depending on complexity.
Q5: Do you provide technical support or installation guidance?
Yes. We provide full technical documentation, remote guidance via video, and can dispatch engineers internationally upon request.
Q6: What is included in your quotation?
Our quotation includes the full RO system, control panel, pumps, pre-treatment units, and all necessary fittings. Installation tools and spare parts can be included upon request.