The difference between NPT, BSPP and BSPT seals

Pressure systems in the process industry use different ways of sealing depending on the geographical region, size of the pressure system and the environment. There are regional differences in sealing types as well as industry preferences. For example, many pressure systems onboard ships use BSPP adapters while many applications in the oil and gas industry use NPT fittings. While one sealing style is not inherently better than another each style has its application.

NPT Connections

NPT Connections

NPT (National Pipe Thread) seals are the most popular type of seal for pressure calibration systems in the U.S. and Canada. NPT male adapters have a taper thread that wedges into the female NPT adapter. They seal due to the “out of roundness principle” which means that the male stretches the female fitting until there is so much force that the connection can hold pressure. One of the challenges with this design is that if you connect stainless steel to stainless steel then over-tightening or poor lubrication can cause gauling and damage to the threads. Thread sealant is needed to seal but only 2 turns of thread sealant is required. Any more than that and the seal can leak around the thread sealant. Ralston Instruments has a wide variety of male NPT adapters , male Quick-disconnect NPT adapters, male NPT calibrator adapters, female NPT adapters, female NPT gauge adapters and female Quick-disconnect NPT gauge adapters.

BSPT Connections

BSPT Connections

BSPT (British Standard Pipe Thread) is similar to NPT except there are important differences. The angle across the flanks of threads (if you sliced the fitting in half long-ways and measured the angle from root to crest to root) is 55 degrees instead of 60 degrees as it is for NPT. Another important difference is that for many BSPT pipe sizes the thread pitch is different than NPT. Thus an NPT male will sometimes fit into a BSPT fitting or vice versa but they will not seal. This is a popular fitting in China and Japan but is very rarely used in North America unless the equipment to which it is attached was imported. Thread sealant is needed to seal the male and female fitting together. Ralston Instruments has adapters to both male BSPT adapters and female BSPT adapters.

BSPP Connections

BSPP Connections

BSPP (British Standard Parallel Pipe) is most popular in the UK, Europe, Asia, Australia, New Zealand and South Africa. It is a parallel thread fitting that uses a bonded seal ring to do the sealing. This bonded ring seal is sandwiched in-between a shoulder on the male fitting and the face of the female fitting and is squeezed in place. BSPP pressure gauges have a longer male thread and use a copper crush washer that is squeezed in between the bottom of the male fitting and the bottom of the female BSPP hole forming a pressure tight seal. No thread sealant is needed to form a seal. Ralston Instruments has male BSPP adapters , female BSPP adapters, female BSPP gauge adapters, and female BSPP Quick-disconnect gauge adapters.

New Test Equipment – Moveable Spectrograph

Jinan Hyupshin Flanges Co., Ltd have a new important test equipment – Moveable Spectrograph, the spectrograph can test raw material, also can test end products of flanges in workshop, it is moveable!

From the equipment, we can test raw material and end products of flanges in easy and fast, make sure supply quite good quality flanges to all clients.

What is “PED”

Pressure equipment and gas appliances

Pressure Equipment Directive (PED):

The Pressure Equipment Directive (97/23/EC) was adopted by the European Parliament and the European Council in May 1997. It has initially come into force on 29 November 1999. From that date until 29 May 2002 manufacturers had a choice between applying the pressure equipment directive or continuing with the application of the existing national legislation. From 30 May 2002 the pressure equipment directive is obligatory throughout the EU.
The directive provides, together with the directives related to simple pressure vessels (2009/105/EC), transportable pressure equipment (99/36/EC) and Aerosol Dispensers (75/324/EEC), for an adequate legislative framework on European level for equipment subject to a pressure hazard.

The PED Directive pdfбългарски (bg)czech (cs)dansk (da)Deutsch (de)eesti (et)ελληνικά (el)español (es)Français (fr)Gaeilge (ga)italiano (it)latviešu (lv)lietuvių (lt)magyar (hu)Malti (mt)Nederlands (nl)polski (pl)português (pt)română (ro)slovenčina (sk)slovenščina (sl)suomi (fi)svenska (sv) arises from the European Community’s Programme for the elimination of technical barriers to trade and is formulated under the “New Approach to Technical Harmonisation and Standards”. Its purpose is to harmonise national laws of Member States regarding the design, manufacture, testing and conformity assessment of pressure equipment and assemblies of pressure equipment. It therefore aims to ensure the free placing on the market and putting into service of the equipment within the European Union and the European Economic Area. Formulated under the New Approach the directive provides for a flexible regulatory environment that does not impose any detailed technical solution. This approach allows European industry to develop new techniques thereby increasing international competitiveness. The pressure equipment directive is one of a series of technical harmonisation directives for machinery, electrical equipment, medical devices, simple pressure vessels, gas appliances etc.

The Directive concerns items such as vessels, pressurised storage containers, heat exchangers, steam generators, boilers, industrial piping, safety devices and pressure accessories. Such pressure equipment is widely used in the process industries (oil & gas, chemical, pharmaceutical, plastics and rubber and the food and beverage industry), high temperature process industry (glass, paper and board), energy production and in the supply of utilities, heating, air conditioning and gas storage and transportation.

Under the Community regime of the Directive, pressure equipment and assemblies above specified pressure and/or volume thresholds must:

  • be safe;
  • meet essential safety requirements covering design, manufacture and testing;
  • satisfy appropriate conformity assessment procedures; and
  • carry the CE marking and other information.

Pressure equipment and assemblies below the specified pressure / volume thresholds must:

  • be safe;
  • be designed and manufactured in accordance with the sound engineering practice of a Member State; and
  • bear specified markings (but not the CE marking).

Basic Requirements for Material and Flanges

Basic requirements for Material and Flange
Requirements are valid for normal situation, in special you have to contact us to introduce.
Material Test basis / Requirements Delivery Condition
 C 22.8 (1.0460)  DIN 17243: 01.87 + VdTUEV – WB 350/3: 2009  +N
 DIN 17243: 01.87
 VdTÜV – WB 350/3: 2009
 P250GH (1.0460)  DIN EN 10222-2: 04.2000  +N
  National Annex
 P245GH (1.0352)  EN 10222-2:1999-12 + AC : 2000-02  +N
 A105N / C21  ASTM A105/A105M-05/ ASME BPVC Sec.2 Part.A:04  +N
  + VdTUEV399/3: 1996-09
  + NACE MR 0175: 2000
 A105N  ASTM A105/A105M-05/ ASME BPVC Sec.2 Part.A:04  +N
  + NACE MR 0175: 2000
 C21 (1.0432)  VdTUEV – WB 399/3: 1996-09  +N
 RSt 37-2 (1.0038)  DIN 17100: 1980-01  +N
 S235JR (1.0038)  DIN EN10025-2: 2005-04  +N
 16Mo3 (1.5415)  DIN EN10222-2:1999-12 + AC:2000-02  +N
 WStE355 / TStE355  DIN EN17103 :1989-10, + VdTUEV-WB 354/3 : 2001-06  +N or QT
  (1.0565 / 1.0566)
 P355NH  (1.0565)  DIN EN10222-4: 1998 + A1: 2002-12  +N
 WStE355 / P355NH  DIN EN17103 :1989-10, + VdTUEV-WB 354/3 : 2001-06  +N or QT
  (1.0565)   + DIN EN10222-4: 1998 + A1: 2002-12
    + DIN EN17103 :1989-10
    + DIN EN10222-4: 1998 + A1: 2002-12
 1.4301 (X5CrNi17-10)  DIN EN10222-5: 2000-02  +AT
 1.4306 (X2CrNi19-11)  DIN 17440:1996-09  +AT
 1.4401 (X5CrNiMo17-12-2)  DIN EN10222-5: 2000-02  +AT
 1.4404 (X2CrNiMo17-12-2)  DIN EN10222-5: 2000-02  +AT
 1.4432 (X2CrNiMo17-12-3)  DIN EN10222-5: 2000-02  +AT
 1.4541 (X6CrNiTi18-10)  DIN EN10222-5: 2000-02  +AT
 1.4571 (X6CrNiMoTi17-12-2)  DIN EN10222-5: 2000-02  +AT
 1.4541 / F321  DIN EN10222-5: 2000-02 / +ASTM A 182/A 182M :2005  +AT
 1.4571 / F316Ti  DIN EN10222-5: 2000-02 / +ASTM A 240  +AT
 1.4404 / F316L  DIN EN10222-5: 2000-02 / +ASTM A 182/A 182M :2005  +AT
 1.4306 / F304L  DIN 17440.1996-09 / +ASTM A 182/A 182M : 2005  +AT
 1.4307 / F304L  DIN EN10222-5: 2000-02 / +ASTM A 182/A 182M :2005  +AT
Flange Test basis / Requirements
 DIN, Carbon Steel  DIN2519:1991-06
  + AD2000-W9: 02.04; -W13/ TRD107;TRB100;
  + Directive 97/23/EG Annex I, Chap. 4.3: 1998-02
 DIN, corrosion-resistant Steel  DIN2519:1991-06
  + AD2000-W9: 02.04; -W2; -W10 / TRD107; TRB100;
  + Directive 97/23/EG Annex I, Chap. 4.3: 1998-02
 DIN EN 1092-1, Carbon Steel  DIN EN 1092-1: 2008-09
  + AD2000-W9; -W13/TRD107;TRB100
  + Directive 97/23/EG Annex I, Chap. 4.3: 1998-02
 DIN EN 1092-1, Stainless Steel  DIN EN 1092-1: 2008-09
  + AD2000-W9; -W2; -W10/ TRD107; TRB100
  + Directive 97/23/EG Annex I, Chap. 4.3: 1998-02
 ANSI  ASME B16.5:2003
 ASME B16.47:2006
Basic requirements for Material and Fitting
Requirements are valid for normal case, in special case you have to contact the technical department.
Material Test basis / Requirements Delivery Condition
 1.4541 (X6CrNiTi18-10)  DIN 17458:1996-09 +AT
 1.4571 (X6CrNiMoTi17-12-2)  DIN 17458:1996-09 +AT
Fittings Test basis / Requirements
 DIN2609 Stainless Steel  VdTUEV –MB 1252/ AD2000- W2; W10/TRD107;TRB100
 T-Piece  Directive 97/23/EG Annex I, Chap. 4.3:1998-02
 Bow  DIN2615-1
 Reducer  DIN2605-1

The differents between forged flange and casting flange

what is the difference between the forged flanges and casting flanges? The answer is: when forging, the organization of the materials will be high internal pressure and defects will disappear and the density increase, make the internal organization of more uniform, and at the same time, make the continuous mechanical properties improve greatly. After forging, must heat treatment. This is the performance different between casting flange and  forging flanges.

The streamlined and the organization of forging is good, dense is good too, but the internal organization and streamline of casting part is poor (if it is cutting part, streamline is worse)

Forging part can withstand the shear strength and tensile force higher  than casting part.

Casting flanges, blank shape and size accurate, manufactured. Low cost. But small have cast defects (vent. Crack with).

Forging flanges internal organization. Mechanical performance is better than even casting flange forging process. Not also can appear grain big or not all. Sclerosis crack phenomenon. Forging costs than casting flange.

Forging flanges flanges carbon than general casting low is not easy to rust

If the shape is simpler, or forging a little bit better, word of batch production cost is not very tall, and forging can receive more even than the organization, the mechanical properties of casting is much better.
If the shape only consider using complex casting method.

Forging of various performance than the casting far. Cost and also higher than that of casting. Often used to teach important forging work conditions, often the working pressure, temperature, medium parameter determination. This flange standards and your design product standards to have specific provision.

Pingpu Road, Niupai, Mingshui, 
Zhangqiu City, Shandong,
China - 250 200

Engineering :
Sales Manager : Austin. Guo
Tel :	+86-531-832 977 28 ext 8001
Fax :	+86-531-832 977 28 ext 8007
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Pipe flanges

There are many different flange standards to be found worldwide. To allow easy functionality and inter-changeability, these are designed to have standardised dimensions. Common world standards include ASA/ANSI (USA), PN/DIN (European),[1] BS10 (British/Australian),[2] and JIS/KS (Japanese/Korean).

In most cases these are not interchangeable (e.g. an ANSI flange will not mate against a JIS flange). Further, many of the flanges in each standard are divided into “pressure classes”, allowing flanges to be capable of taking different pressure ratings. Again these are not generally interchangeable (e.g. an ANSI 150 will not mate with an ANSI 300). These pressure classes also have differing pressure and temperature ratings for different materials. Unique pressure classes for piping can also be developed for a process plant or power generating station; these may be specific to the corporation, engineering procurement and construction (EPC) contractor, or the process plant owner.

The flange faces are also made to standardized dimensions and are typically “flat face”, “raised face”, “tongue and groove”, or “ring joint” styles, although other obscure styles are possible.

Flange designs are available as “welding neck”, “slip-on”, “boss”, “lap joint”, “socket weld”, “threaded“, and also “blind”.

ASME standards (U.S.)

ASME type flange on a gas pipeline

Pipe flanges that are made to standards called out by ASME B16.5 or ASME B16.47 are typically made from forged materials and have machined surfaces. B16.5 refers to nominal pipe sizes (NPS) from ½” to 24″. B16.47 covers NPSs from 26″ to 60″. Each specification further delineates flanges into pressure classes: 150, 300, 400, 600, 900, 1500 and 2500 for B16.5; B16.47 delineates its flanges into pressure classes 75, 150, 300, 400, 600, 900.

The gasket type and bolt type are generally specified by the standard(s); however, sometimes the standards refer to the ASME Boiler and Pressure Vessel Code (B&PVC) for details (see ASME Code Section VIII Division 1 – Appendix 2). These flanges are recognized by ASME Pipe Codes such as ASME B31.1 Power Piping, and ASME B31.3 Process Piping.

Materials for flanges are usually under ASME designation: SA-105 (Specification for Carbon Steel Forgings for Piping Applications), SA-266 (Specification for Carbon Steel Forgings for Pressure Vessel Components), or SA-182 (Specification for Forged or Rolled Alloy-Steel Pipe Flanges, Forged Fittings, and Valves and Parts for High-Temperature Service). In addition, there are many “industry standard” flanges that in some circumstance may be used on ASME work.

Other countries

Flanges in other countries also are manufactured according to the standards for materials, pressure ratings, etc. Such standards include DIN, BS,[3] and/or ISO standards.

Pipe-to-pipe connections between different joint types

Molded raised faces for swaged PP-lined pipe are shown in many connections illustrated here, however, reinforced flared faces (PVDF and PTFE) may be used in most of the same connections.

Note: Normally no gaskets are required between plastic lined piping components. When lined piping is connected to a flange face of another material, a gasket shall be installed. 

Figure 1 – Connection of molded raised face to gasket plastic-lined pipe

  Figure 2 – Connection of reinforced flared face to gasket plastic-lined pipe

Figure 3 – Providing low-angle bend using tapered face spacer

Steel sawing machines

Steel sawing machines used for steel cutting, the samller cutting steel using to flanges forging works.