China Made Solid BPV thread Ring gages per API 6A/API 5A
2”-4 HBPV LH Thread Ring Gage，3”-4 HBPV LH Thread Ring Gage，4”-4 HBPV LH Thread Ring Gage，5”-4 HBPV LH Thread Ring Gage，6 1/2”-2 HBPV LH Thread Ring Gage，
2 1/2”-4 HBPV LH Thread Plug Gage，3 1/2”-4 HBPV LH Thread Plug Gage，4 1/2”-4 HBPV LH Thread Plug Gage，5 1/2”-4 HBPV LH Thread Plug Gage，6 5/16”-2 HBPV LH Thread Plug Gage，

Precision BPV (Back Pressure Valve) Thread Gages – API 6A / API 5A Standard

Introduction to BPV Thread Gages

BPV (Back Pressure Valve) thread gages are precision inspection tools designed for verifying back pressure valve threads commonly used in oilfield equipment, wellhead components, and offshore drilling machinery. These threads feature a 90° thread angle and are available in 4 TPI (threads per inch) and 2 TPI configurations, conforming to the stringent requirements of API 6A (Wellhead and Christmas Tree Equipment) and API 5A specifications.

The thread form follows the design criteria of ASME B1.5 Acme threads, characterized by its 90° included angle and specific pitch diameter tolerances. In the petroleum industry, these are also referred to as HBPV threads, where "H" denotes the H-type back pressure valve thread commonly found on tubing hangers and back pressure valve assemblies.

BPV thread gages are manufactured as both GO and NOGO gages, ensuring that product threads fall within acceptable dimensional limits. They are typically designated with "LH" for left-hand threads, while right-hand threads are unmarked by default.

Available BPV Thread Gage Models

Sowant Precision Gages offers a complete range of BPV thread ring gages and thread plug gages to meet all oilfield inspection requirements.

BPV Thread Ring Gages (for External Thread Inspection)

BPV Thread Plug Gages (for Internal Thread Inspection)

Note: The number before the thread pitch (e.g., "-4" or "-2") indicates the nominal size in inches, while the number after represents the threads per inch. All listed models feature Left-Hand (LH) thread orientation.

Key Specifications

• Thread Form: BPV (Back Pressure Valve) / HBPV

• Applicable Standards: API 6A, API 5A, ASME B1.5 (Acme thread design criteria)

• Thread Angle: 90° included angle

• Thread Pitch: 4 TPI and 2 TPI

• Rotation: Left-Hand (LH) as standard for these models

• Gage Type: Working gages (GO/NOGO) for product thread inspection

Comprehensive Thread Gage Manufacturing Capabilities – API Spec 5B / API Spec 7-2 and International Standards

Sowant Precision Gages (SOWANT PRECISION GAGE CO., LTD.) is a professional thread gage manufacturer based in China, dedicated to providing high-precision measurement solutions for the global petroleum, aerospace, automotive, and general manufacturing industries. As a specialized thread gage producer, Sowant Precision Gages offers short delivery times and consistent high quality, ensuring that customers receive reliable inspection tools when they need them most.

API Spec 7-2 Rotary Shouldered Connection Thread Gages

Sowant Precision Gages manufactures a complete range of thread gages for rotary shouldered connections in accordance with API Spec 7-2 (Threading and Gauging of Rotary Shouldered Thread Connections), which is technically identical to ISO 10424-2 . These gages are available for both NC (Numbered Connection) and REG (Regular) styles, covering all popular sizes used in drill-string components.

NC (Numbered Connection) Thread Gages – API Spec 7-2

NC connections feature the V-0.038R, V-0.040, V-0.050, or V-0.055 thread forms and are the most common rotary shouldered connections in the industry . The table below lists available NC thread ring and plug gages with their specifications:

REG (Regular) Style Thread Gages – API Spec 7-2

REG connections are rotary shouldered connections featuring the V-0.040, V-0.050, or V-0.055 thread forms . They are typically used for smaller drill string components and in applications requiring higher tensile strength. Available REG thread gages include:

Additional API Spec 7-2 Connection Types

In addition to NC and REG connections, Sowant Precision Gages manufactures thread gages for other rotary shouldered connection types per API Spec 7-2:

• FH (Full Hole) Style Connections – Featuring V-0.040 or V-0.050 thread forms 

• IF (Internal Flush) Connections – Featuring V-0.038R thread forms 

• H90 Connections – Rotary shouldered connections with 90° thread forms 

• SLH90 Style Connections – 90° thread forms with heavy truncation 

API Spec 5B Thread Gages

Sowant Precision Gages also manufactures a comprehensive range of thread gages per API Spec 5B for casing, tubing, and line pipe threads :

Casing Thread Gages

• Short Thread Casing (STC) – Round thread form

• Long Thread Casing (LTC) – Round thread form

• Buttress Thread Casing (BTC) – Trapezoidal thread form

Tubing Thread Gages

• Non-Upset Tubing (NU) – For standard tubing connections

• External Upset Tubing (EUE) – For high-strength tubing applications

Line Pipe Thread Gages

• Line Pipe Threads – For pipeline connections per API Spec 5B

American Standard Thread Gages (ASME)

ASME B1.2 – Unified Thread Gages (UN/UNR)

Sowant Precision Gages manufactures unified thread ring and plug gages per ASME B1.2 for all UN thread series :

• UNC (Coarse thread series)

• UNF (Fine thread series)

• UNEF (Extra fine thread series)

• UN (Constant pitch series)

• UNS (Special thread series)

ASME B1.5 – Acme Thread Gages

Complete range of ACME 29° thread ring and plug gages per ASME B1.5 :

• General Purpose (2G, 3G, 4G tolerance classes)

• Available sizes: 1/4-16 ACME through 2-4 ACME and larger custom sizes

ASME B1.8 – Stub Acme Thread Gages

Stub Acme 29° thread gages per ASME B1.8 for applications requiring shallow thread depth :

• Reduced thread height (0.3P vs. 0.5P for standard Acme)

• Available in all standard Stub Acme sizes

ASME B1.9 – Buttress Thread Gages

Buttress thread ring and plug gages per ASME B1.9 featuring 7°/45° thread angle :

• Designed for high thrust load applications

• Available in all standard buttress sizes

International Standard Thread Gages

ISO Metric Thread Gages

Sowant Precision Gages manufactures metric thread gages per ISO 965 specifications :

• ISO Metric Coarse (M) – Standard metric thread series

• ISO Metric Fine (MF) – Fine pitch metric threads

• Tolerance classes: 4H/4h through 8H/8h

DIN Standard Thread Gages

German standard thread gages manufactured per DIN specifications:

DIN 405 Round Thread Gages :

• 30° round thread form

• Used for fire fighting equipment, food industry pipe couplings, and railway applications

• Available in external and internal configurations

• Standard TPI: 10, 8, 6, 4 TPI

Additional DIN Thread Gages:

• DIN 13 – Metric ISO threads

• DIN 103 – Metric trapezoidal threads

• DIN 513 – Buttress threads

Tr Metric Trapezoidal Thread Gages

Metric Trapezoidal (Tr) thread gages with 30° thread angle per ISO 2904 and DIN 103 standards :

• Tr 8×1.5 through Tr 100×20 and larger

• Tolerance classes: 7H/7e, 8H/8e, 9H/9c

• Left-hand (LH) available upon request

GOST Standard Thread Gages

Russian standard thread gages manufactured per GOST specifications :

• GOST 17757-1972 – Thread plug gages with incomplete thread

• GOST 17760-1972 – Thread plug gages for diameters 52-100mm

• GOST 17764-1972 – Thread ring gages with incomplete thread

• GOST 17766-1972 – Thread ring gages for diameters 105-300mm

Quality Assurance

Sowant Precision Gages utilizes full CNC machining and high-precision thread scanning equipment to perform 100% full-parameter inspection on all gages. This ensures that every gage meets the exacting requirements of the applicable standards and provides trustworthy, repeatable measurements on the production floor.

All gages feature:

• Premium materials: GCr15 bearing steel, alloy tool steel, case-hardened steel 

• Hardness: 58-62 HRC minimum on measuring surfaces

• Complete certification documentation

• Traceability to national and international standards

Why Choose Sowant Precision Gages?

• Short delivery times – Extensive stock of popular sizes

• High quality – 100% inspection with advanced metrology equipment

• Comprehensive capabilities – One-stop source for all thread gage requirements

• Expert technical support – Experienced engineers familiar with international standards

For inquiries or to place an order, please contact Sowant Precision Gages directly.