90° Anti-Blowback Swivel Adapter 5/16" to 1/4"
90° Anti-Blowback Swivel Adapter 5/16" to 1/4"
90° Anti-Blowback Swivel Adapter with promotional text about HVAC service and refrigerant loss.
Brass HVAC fitting with features listed on a black label against a blurred background
Brass fitting adapter with technical specifications on a gray background
HCPRO brass adapter with hose and comparison chart on a blurred background
Gold HVAC adapter with text about precision-engineered design for leak-free service on a blurred background.
Gold制冷剂连接器与HCPRO宣传文本，强调服务兼容多种现代制冷剂。
90° Anti-Blowback Swivel Adapter 5/16" to 1/4"
90° Anti-Blowback Swivel Adapter 5/16" to 1/4"
90° Anti-Blowback Swivel Adapter 5/16" to 1/4"
Black Knight Series logo with a helmeted figure on a white background
90° Anti-Blowback Swivel Adapter 5/16" to 1/4"
Black Knight
Anti-Blowback

HCABB51690° anti-blowback swivel — depresses the core only when connected, zero refrigerant loss

SKU · 22-0097MPN · HCABB51690
A2L Safe90° Swivel5/16" × 1/4"Sealed Core
$8.56$16.95
Factory-DirectSave $8.39
In stock· ships same business day from Miami
Direct from the manufacturer — Miami HQ, full warranty & tech support included.
Adapter Quantity
Adapter Quantity: Each
In stock, ready to ship
Designed
In Miami, USA
Warranty
1-Year Full
Ships
1–2 Days
  • Field-tested by working HVAC technicians
  • Free returns within 30 days
  • Direct manufacturer support — Miami HQ
  • ORDER IN THE NEXT — AND IT SHIPS TODAY FROM MIAMI
0BLOWBACK
No Venting on Disconnect

Internal check valve closes the instant you disconnect — no refrigerant blowback, no vapor cloud, no lost charge every time you break the connection

608COMPLIANT
EPA Low-Loss Fitting

Low-loss anti-blowback fitting meets EPA Section 608 service-practice standards — keep refrigerant in the system, not in the air

BRASSSAE
Precision Brass Build

Solid brass body with precision SAE threads and a spring check valve — rated for R-410A and A2L high-pressure service. See hero pills for this model's sizes.

HCPRODESIGNED
Built to Black Knight Spec

HCPRO-designed to Black Knight specifications and quality-control standards — engineered in Miami, built to spec by our manufacturing partner

Why Black Knight

Zero blowback.

EPA 608 compliant.

Solid brass.

HCPRO Black Knight anti-blowback adapters seal the instant you disconnect — no refrigerant venting, no lost charge, EPA Section 608 compliant. Solid brass with a spring check valve, in swivel and straight configurations. See hero pills for this model's size.

Anti-blowback check valve

The internal spring check valve closes automatically the instant you disconnect from the service port — sealing the refrigerant inside the adapter instead of venting it into the air. Three wins on every disconnect: you don't lose 1-2 oz of refrigerant, you don't fog the work area with vapor, and you stay compliant with EPA Section 608 service-practice standards. Standard adapters vent every single time. These don't.

EPA 608 low-loss compliance

EPA Section 608 requires low-loss fittings on refrigerant service connections — and beyond the regulation, refrigerant is expensive and getting more so. R-410A and the new A2L blends cost real money per pound. An anti-blowback adapter pays for itself in saved refrigerant across a season of service calls, while keeping you on the right side of the regs.

Solid brass, swivel or straight

Machined solid brass with precision SAE threads and a reliable spring check valve. Available in 90° swivel (for tight engine bays and condenser compartments) and straight configurations, in 5/16″→1/4″ and 1/4″→1/4″ sizes. See the hero pills for this model's exact configuration and size.

Full Product Description

The HCPRO Black Knight HCABB516 is a 90° anti-blowback swivel adapter that depresses the Schrader core only once connected — so you make and break connections with zero refrigerant loss.

Key features

  • Anti-blowback core seal — no refrigerant venting when you connect or disconnect
  • 90° swivel reaches tight service ports and relieves hose strain
  • 5/16" × 1/4" — connects R-410A 5/16" ports to 1/4" tooling
  • Forged brass with a sealed core mechanism, high-pressure rated
  • HCPRO-designed to Black Knight specifications

Protect your charge on every R-410A and A2L connection.

Technical specifications

Anti-blowback adapter specs that keep refrigerant in the system.

HCPRO Black Knight anti-blowback adapter — solid brass, spring check valve, EPA 608 low-loss. Seals the instant you disconnect, no refrigerant venting. Swivel and straight configurations. See hero pills for this model's size. HCPRO-designed to Black Knight specifications.

Type
Anti-blowback (low-loss) SAE adapterSpring check valve seals refrigerant on disconnect — see hero pills for this model
Material
Solid machined brassCorrosion-resistant, holds high-pressure service without weeping
Size conversion
See hero pills / product titleHCABB51690: 90° 5/16″→1/4″ · HC-ABB516: straight 5/16″→1/4″ · HCABB14: straight 1/4″→1/4″ · HCABB1490: 90° 1/4″→1/4″
Check valve
Spring-loaded, auto-closeSeals the instant you disconnect — no manual valve to remember
EPA compliance
Section 608 low-loss fittingMeets federal refrigerant service-practice standards
Configuration
90° swivel or straight (per model)90° swivel for tight access; straight for open connections
Pressure rating
R-410A / A2L high-pressureHolds under full HFC and A2L service pressure
Compatible refrigerants
R-410A, R-22, R-134a, R-404A, R-32, R-454BAll common HFC and A2L refrigerants
Refrigerant saved
~1-2 oz per disconnect avoidedPays for itself across a season of service calls
Brand
HCPRO Black KnightThe HCPRO professional HVAC service tool line
Seal
SAE flare — no tape requiredMetal-to-metal flare seal plus internal check valve
Country of origin
ChinaHCPRO-designed in Miami to Black Knight specifications, built to spec and quality-controlled to OEM standards
Best paired with
Charging hoses, manifoldsAdd anti-blowback protection to any standard SAE connection
Warranty
1-year limitedCovers manufacturing defects under normal professional use
In the box

The anti-blowback adapter, ready to stop venting refrigerant.

The anti-blowback adapter, ready to stop venting refrigerant.
HCPRO Black Knight anti-blowback adapterSolid brass with internal spring check valve — see hero pills for this model's size and configuration
Spring check valve (internal)Auto-closes on disconnect — no refrigerant venting, no manual valve to operate
SAE flare sealsMetal-to-metal flare — leak-free when seated, no thread tape needed
Black Knight fitting referenceAnti-blowback usage, EPA 608 notes, size conversion, refrigerant compatibility
Customer reviews

What working techs say after putting it on the truck.

12,000+ HVAC pros served
4.9★ Average rating
94% Repeat buyers

Replace this with a real customer quote — how much refrigerant it saved, EPA compliance, how the check valve performed on disconnect.

Marcus T.HVAC TECH · MIAMI, FL
On HCPRO Black Knight Anti-Blowback Adapter

Replace this with a real customer quote — how much refrigerant it saved, EPA compliance, how the check valve performed on disconnect.

Jorge R.REFRIGERATION CONTRACTOR · ATLANTA, GA
On HCPRO Black Knight Anti-Blowback Adapter

Replace this with a real customer quote — how much refrigerant it saved, EPA compliance, how the check valve performed on disconnect.

Derrick W.COMMERCIAL HVAC · PHOENIX, AZ
On HCPRO Black Knight Anti-Blowback Adapter
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Tools that pair with the HCABB516.

Common questions

Answers from the warehouse floor.

Still stuck? Call our techs at 305-720-0044.

Does HCPRO warranty the products?

Yes — every HCPRO Black Knight product ships with a 1-year limited warranty against manufacturing defects under normal professional use. We'll replace the manifold, gauges, or hoses if they fail to meet stated specs. See our full warranty terms.

Which anti-blowback adapter do I need?

Match size + access. HCABB51690 (90° swivel, 5/16″→1/4″) and HC-ABB516 (straight, 5/16″→1/4″) connect 1/4″ hoses to R-410A 5/16″ ports. HCABB14 (straight, 1/4″→1/4″) and HCABB1490 (90° swivel, 1/4″→1/4″) add anti-blowback to standard 1/4″ connections. Pick the 90° swivel for tight spaces, straight for open ports.

How does anti-blowback work?

An internal spring-loaded check valve stays open while connected (full flow) and snaps closed the instant you disconnect. The refrigerant that would normally blow out of the hose/port junction is sealed inside instead. No manual valve to remember, no timing it — it just works every disconnect.

Is this required by EPA?

EPA Section 608 requires low-loss fittings on refrigerant service hoses and connections to minimize venting during service. Anti-blowback adapters are one way to meet that standard on connections that aren't already low-loss. Beyond compliance, they save you real money — R-410A and A2L refrigerants are expensive, and 1-2 oz per disconnect adds up fast.

What refrigerants and pressures?

All common HFC and A2L — R-410A, R-22, R-134a, R-404A, R-32, R-454B — at full high-pressure service conditions. Brass body and check valve hold R-410A high-side pressure without weeping.

Can I add these to my existing hoses?

Yes — that's the point. Thread an anti-blowback adapter onto any standard 1/4″ or 5/16″ SAE hose end and you've upgraded that connection to low-loss without buying new hoses. A set of these turns your existing charging hoses into EPA-compliant, refrigerant-saving connections.

Swivel or straight?

The 90° swivel versions (HCABB51690, HCABB1490) angle the hose away and rotate freely — for tight engine bays, packed condensers, mini-splits. The straight versions (HC-ABB516, HCABB14) are for open, accessible ports. Swivel works everywhere; straight is lower-profile when space allows.

Can I return an unused adapter?

Yes — free returns within 30 days for unused adapters in original packaging. Read our full return policy.

Do you offer bulk pricing?

Yes — trade pricing here, volume discounts for shops outfitting trucks with low-loss fittings. Email hcproproductsusa@gmail.com for a custom quote within 24 hours.