LP21-4040 Low-Pressure RO Membrane – 4″ × 40″, 2,800 GPD

The LP21-4040 Reverse Osmosis Membrane is a low-pressure, high-rejection membrane element designed for brackish-water desalination and commercial or industrial water purification. Its standard 4-inch × 40-inch configuration supports installation in compatible 4040 pressure vessels and multi-element reverse osmosis equipment.

Under specified test conditions, the current LP21-4040 configuration provides a nominal permeate flow of 2,800 gallons per day, or approximately 10.6 cubic meters per day, with a stable salt-rejection rate of 99.6%. Its performance makes it suitable for applications requiring effective dissolved-solids reduction and high-quality permeate from appropriately pretreated feedwater.

The spiral-wound element provides approximately 100 square feet of active membrane area and uses a 28-mil feed spacer. The membrane is engineered for treating qualifying brackish water, groundwater, surface water and municipal water with higher dissolved-solids concentrations than those normally recommended for ultra-low-pressure elements.

Proper pretreatment is essential for controlling sediment, hardness, scale, iron, silica, organic fouling and oxidizing chemicals. Feedwater chemistry, required recovery, operating pressure and target permeate quality should be evaluated during system design.

Technical Specification

Testing Conditions

Testing Pressure: 225 psi (1.55MPa)

Testing Solution Temperature: 25 ℃

Concentration of Testing Solution (NaCl): 2000ppm

pH value of Testing Solution: 7.0±8.5

Recovery Rate of Single Element: 15%

Key Features

• Low-pressure operation for reduced energy demand
• High salt and TDS rejection performance
• Thin Film Composite (TFC) membrane technology
• Standard 4.0″ × 40″ (4040) membrane format
• Stable permeate flow under typical municipal pressures
• Long service life with proper pretreatment
• Ideal for commercial and industrial RO applications

Applications

◎ Drinking water production, such as: packaged water, direct drinking water, food processing water, etc.

◎ Purified water production, such as: pharmaceutical water, medical water, electronics water, etc.

Shipping Information

Optimal Purity Solutions is committed to fast, reliable, and professional fulfillment for our authorized dealer network.

Fulfillment & Processing

• Order Processing: Most in-stock orders ship within 1–2 business days

• Custom/OEM Builds: Lead times vary by configuration; your sales representative will confirm timelines

Shipping Coverage

• Domestic: Nationwide shipping throughout the United States

• International: Available for qualified distributors (terms and transit times vary)

Carriers & Methods

• Shipments are sent via trusted national freight and parcel carriers

• LTL/FTL freight available for pallets and bulk orders

• Expedited shipping options available upon request

Packaging & Handling

• Products are professionally packaged to protect against damage in transit

• Palletized and freight shipments are secured and labeled to industry standards

Tracking & Support

• Tracking information is provided once your order ships

• Our logistics team is available to assist with routing, delivery coordination, and special requirements

Important Notes

• Shipping costs are calculated based on weight, dimensions, destination, and service level

• Damages or discrepancies must be reported within 48 hours of delivery

• Products are sold exclusively through authorized water treatment dealers and partners