ISO 9001:2015 Certified BBB A+ Accredited Available 24/7/365 Same-Day Shipping on Stocked Items Manufactured In-House 100% USA Materials

High Pressure Isolation & Testing Products

GripSafe® ST DBB Double Block & Bleed Isolation & Test Plug

Two seals with a test and bleed space between them, so you can prove the isolation is holding before and during the job. Isolate live lines, test weld-neck flanges, and hydrotest open-ended pipe without welding end caps. Back pressure up to 10,000 psi. Sizes 3/4" to 36", to rent or buy. Find your size ›

Get the USA Industries Technical Tools app

GripSafe ST DBB double block and bleed plug family, 3/4 inch to 36 inch

GSST DBB Family, 3/4" to 36"‹›

30 inch Schedule 80 custom GripSafe ST DBB plug

30" Sch 80 Custom GSST DBB‹›

Small body GripSafe ST DBB plug with extension

Small Body GSST DBB‹›

Medium Size GSST DBB‹›

GripSafe DBB plug in pipe with Pipe Reinforcement Device

DBB with Pipe Reinforcement Device‹›

Get a Quote or Order

Send us these details and we'll respond the same business day.

GSST plug model (DBB)
Pipe size and schedule
Test pressure
Quantity needed
Rental or purchase
Date needed

Get A Quick Quote Call (800) 456-8721

Technical Data Sheet

GripSafe® ST DBB

DS-GSST-DBB-001 Rev. Current

Specification	Details
Sizes	3/4" – 36" (larger and custom on request)
Schedules	10 through XXH (see size chart)
Back Pressure Rating	Up to 10,000 psi (varies by size and schedule)
Between-Seals Test Pressure	2,500 psi (all configurations)
Seals	Two Tri-Ply® multi-durometer seals
Gripping	Self-adjusting wedges • Gritlock® surface
Body	Aviation-grade aluminum
Ports	Fill port • Back pressure vent (thread sizes per plug)
Temperature	−10°F to 170°F continuous • 200°F intermittent
Body Styles	Small body, 3/4" – 4" • Large body, 4" and up (4" Sch 120, 160, XXH use the small body)
Availability	Rent • Purchase

ASME StandardB16.5

ASME StandardB31.1 / B31.3

ASME StandardPCC-2-2018

The Basics

What Is the GripSafe® ST DBB?

DBB stands for double block and bleed. The plug seals the pipe with two independent seals, and the space between them can be filled, pressurized, or bled through a port.

Pressurize that space to prove both seals are holding before anyone works downstream, then keep watching it for positive isolation monitoring throughout the job. Like every GripSafe® ST plug, the wedges grip the pipe wall on insertion and grip harder as pressure builds.

Just need to test open-ended pipe? See the GSST ORB. Other options: GSST IIB, GS XL, and the Non-Gripping DBB.

GripSafe ST DBB family of double block and bleed isolation and test plugs — GSST DBB Family of Isolation & Test Plugs

Applications

Where the DBB Is Used

Flange Weld TestingPressure between the seals hydrotests weld-neck flanges for hoop stress failure, weld leaks, or pinhole paths, without unexpected pressure discharge.

Pre/Post Weld OperationsDual ports circulate water between the seals to cool the weld zone during welding (6" and larger).

IsolationProtect crews from hydrocarbon or process leaks if a valve is opened by accident, leaks, or upstream equipment fails.

Positive Isolation MonitoringPressure held between the seals confirms seal integrity and effective pipe isolation.

Line PurgingFeed inert gas through the vent pipe to back-purge welds or remove oxygen.

30 inch Schedule 80 custom GripSafe ST DBB double block and bleed plug — 30" Sch 80 Custom GSST DBB

Medium size GripSafe ST DBB double block and bleed plug — Medium Size GSST DBB

Patented Technology

Key Features

Independently Self-Gripping WedgesGrip on insertion, even before nuts are tightened. Each wedge adjusts on its own to pipe ovality and irregularities, spreading load evenly, and grip increases with test pressure.

Gritlock® Surface TechnologyA brazed texture with thousands of microscopic contact points. Strong grip, minimal marking, and no carbon contamination, so the same plug works in carbon, stainless, and alloy pipe.

Dual Tri-Ply® SealsTwo patented multi-durometer seals resist deformation and edge mushrooming. The space between them tests to 2,500 psi.

Virtually No Pipe DamageNo serrated jaws or sharp edges, so virtually no surface damage or pipe cleanup.

LightweightAviation-grade aluminum. On average lighter than competing plugs, up to 50% lighter in larger sizes.

Temperature−10°F to 170°F continuous, up to 200°F intermittent.

ReusableProven over hundreds of cycles.

Thin Wall & High Pressure

Pipe Reinforcement Device (PRD)

Some pipe needs extra support at higher back pressures.

RequiredWhen testing A106 Grade B pipe, 4" and larger, at a back pressure above the P-value shown in the size chart.

RecommendedStrongly recommended for all Schedule 10/10S and thinner pipe.

Other MaterialsFor pipe other than A106 Grade B, consult our engineering team.

GripSafe DBB plug installed in pipe with a Pipe Reinforcement Device — DBB with Pipe Reinforcement Device

Proven in the Field

What Crews Say

"GripSafe plugs have been valuable assets on the LNGC site. The quick and easy installation, use, and removal of the plugs have made testing plain end pipe simple. The Lifting Device makes rigging of the larger plugs into position fast, convenient, and safe. The design of the grippers leave little to no marks inside the pipe. Torque values and plug info on the front plate makes plug identification and double-checking for the right plug usage easy. Overall, the GripSafe plugs are an excellent product."
T. Read, Hydro Foreman, and S. Daigle · Global EPC Company

Small body GripSafe ST DBB plug with extension, 3/4 inch to 4 inch — Small Body GSST DBB

Pressure Testing Solutions

Test Plugs vs. Welding End Caps

GSST Test PlugsWelded End Caps

SpeedInstalls in minutes, ready to test right awayWeld, cool, test, then grind off. Hours per cycle

CostReusable. No welders, consumables, grinding, or NDESingle-use caps, welder labor, consumables, and inspections

SafetyNo hot work permits, arc flash, fumes, or burnsOpen flame and hot metal. Permits, fire watch, and PPE required

FlexibilityReposition and reuse across spools and test setupsPermanently welded. Changes mean cutting off and starting over

Pipe QualityNo heat-affected zone. Low risk of contamination or distortionHeat-affected zones, possible distortion, post-weld NDE

The Bottom LineIsolation and test plugs transform pressure testing from a bottleneck into a streamlined operation, delivering speed, savings, safety, and flexibility that welding end caps simply cannot match.

Critical Safety ReminderPressure testing is hazardous. Make sure all connections, valves, flanges, and fittings are suitable for the test, and verify the line ID falls within the plug's range. Never stand in front of a test plug or enclosure during testing; a discharge can cause severe injury or death. Follow the full installation procedure in the operating manual, and never exceed the rating of the lowest rated component in the system.

Available to Rent or Buy

Rent GripSafe® for Your Next Turnaround

Rent the plugs you need for the job instead of buying and storing a full set, with our team on call 24/7/365.

Lower Upfront CostPay for the job, not the inventory

No StorageWe keep them between jobs

On Call 24/7/365Support whenever the job needs it

Get A Quick Quote See Rentals

Common Questions

GripSafe® ST DBB FAQ

What does double block and bleed mean?

Two seals block the line, and the space between them can be bled or pressurized. Holding pressure in that space proves both seals are working, which is why DBB is the choice for positive isolation.

How much pressure can the DBB hold?

Back pressure up to 10,000 psi on smaller sizes, varying by size and schedule; check the size chart for your plug. The space between the seals tests to 2,500 psi on every configuration. Never exceed the rating of the lowest rated component in the system.

Can it test weld-neck flange welds?

Yes. Pressurizing the space between the seals tests the flange weld for hoop stress failure, leaks, or pinholes, without welding on a cap. For flange-only testing, also see our Flange Weld Test Plug.

When do I need a Pipe Reinforcement Device?

In A106 Grade B pipe, 4" and larger, when the back pressure will exceed the P-value in the size chart. It's strongly recommended for all Schedule 10/10S and thinner pipe. For other materials, consult our engineering team.

How do I choose the right plug?

Start with pipe size and schedule in the size chart, then confirm the measured pipe ID falls within the plug's recommended ID range. On 6" through 24", the tool OD must be within 1/8" concentricity to the pipe ID. Not sure? Call us and we'll match it for you.

Do you make sizes larger than 36"?

Yes. Larger sizes and custom configurations are available on request.

Can I rent DBB plugs?

Yes, rent or purchase. See rentals.

Intellectual Property