DrainGap Multi-Port Drain Adapter Applications Requiring Air Gaps

QAI US
Certified and Tested to ASME A112.1.3, IAPMO PS 65, NSF 61, & NSF 372
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The ultimate space-saving, code-compliant air gap

When drainage applications require reliable air gaps, the patented DrainGap® Multi-Port Drain Adapter delivers innovation, compliance, and performance in one compact design. Engineered with a first-of-its-kind two-stage integrated air gap, this advanced adapter eliminates splashing and ensures consistent drainage for up to four separate connections—all while saving valuable space, time, and installation costs.

Built for professionals and system designers who demand both efficiency and durability, the DrainGap installs vertically almost anywhere—making it ideal for residential, commercial, and light industrial environments. Whether you’re managing appliance drain lines, water treatment systems, or specialized applications like dialysis, this versatile component ensures seamless performance and long-lasting reliability.

Manufactured from high-strength, non-corrosive Schedule 40 PVC, DrainGap is built to resist chlorine, chloramine, and scale buildup. With 100% lead-free construction and multiple NPT-threaded ports, the system provides flexibility for modern plumbing setups while maintaining strict compliance with plumbing and building codes.

From food service installations to reverse osmosis and deionization systems, DrainGap brings professional-grade drainage performance to every connection—clean, compliant, and maintenance-free.

  • Patented integrated air gap ensures code compliance and minimizes splashing
  • Supports up to four 1/2” female NPT threaded drain connections
  • Built-in output couplings accept 1-1/2”, 2", 3”, or 4” pipe
  • 100% lead-free, durable Schedule 40 PVC construction
  • Resistant to chlorine, chloramine, and scale buildup for worry-free installations
  • Includes proprietary flow adapters to minimize splashing in low-flow applications
DrainGap Multi-Port Drain Adapter - DH154-AG DrainGap Multi-Port Drain Adapter - DH304-AG DrainGap Multi-Port Drain Adapter - DH404-AG
SKU DH154-AG DH304-AG DH404-AG
  • Standard Flow: Up to 3 GPM
  • Output: 1.5" Pipe or 2" Coupling
  • Higher Flow: Up to 7 GPM
  • Output: 3" Pipe
  • Max Flow: Up to 11 GPM
  • Output: 4" Pipe
$ 49.00 $ 588.00 $ 59.00 $ 708.00 $ 59.00 $ 708.00
Integrated Outlet
Packaging

DrainGap Standards Certifications & Compliance

QAI US

Independently tested and certified by QAI Laboritories

QAI Laboratories is a testing, inspection, and certification organization that provides services to ensure the safety, quality, and performance of a wide range of products and systems across various industries. QAI Laboritories has tested and certified DrainGap® to comply with ASME A112.1.3 (Air Gaps), IAPMO PS 65 (Dishwasher Air Gaps), NSF 61 (Drinking Water System Components – Health Effects) and NSF 372 (Drinking Water System Components – Lead Content).

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ASME A112.1.3

Establishes performance and safety requirements for air gaps in plumbing systems, specifying design, materials, and dimensional criteria to ensure effective separation between potable water supplies and potential sources of contamination, thereby preventing backflow and safeguarding public health.

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IAPMO PS 65

IAPMO PS 65 establishes performance and safety requirements for dishwasher air gaps, covering design, materials, construction, and testing to ensure effective prevention of wastewater backflow into potable water systems, thereby protecting water quality and maintaining sanitary plumbing conditions.

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NSF 61

This standard establishes health criteria for materials in contact with drinking water, ensuring they don’t leach harmful substances into the water supply.

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NSF 372

This standard sets criteria for evaluating products to ensure their lead content averages no more than 0.25%, meeting "lead-free" requirements for drinking water systems.

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California HSC 116875

This section bans the use of lead in the installation or repair of public water systems or plumbing in facilities that provide water for human consumption.

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Massachusetts Acceptance

Products must be tested using industry standards to ensure safety and proper function for public use. Certified labs perform these tests to meet guidelines and ensure accurate testing.

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Wisconsin Approval

DrainGap complies with Wisconsin's SPS 382-384, Wisconsin Statutes 145 and 160. Based on these standards, the Department grants alternate approval per section SPS 382.30.

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Tech Specs

  • DH154-AG
    Material
    White PVC
    Inlets
    1/2" FNPT (x4)
    Outlet
    Accepts 1.5" Pipe or 2" Coupling
    Diameter
    4.5"
    Height
    7"
    Weight
    12.9 oz
    Max Operating Temperature
    140° F
    Max Flow Rate (Backsiphonage)
    4 GPM
    Max Flow Rate (Backpressure)
    11 GPM
  • DH304-AG
    Material
    White PVC
    Inlets
    1/2" FNPT (x4)
    Outlet
    Accepts 3" Pipe
    Diameter
    4.5"
    Height
    8.75"
    Weight
    15.1 oz
    Max Operating Temperature
    140° F
    Max Flow Rate (Backsiphonage)
    7 GPM
    Max Flow Rate (Backpressure)
    11 GPM
  • DH404-AG
    Material
    White PVC
    Inlets
    1/2" FNPT (x4)
    Outlet
    Accepts 4" Pipe
    Diameter
    4.5"
    Height
    8.375"
    Weight
    15.1 oz
    Max Operating Temperature
    140° F
    Max Flow Rate (Backsiphonage)
    11 GPM
    Max Flow Rate (Backpressure)
    11 GPM

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