How to get high quality ring type joint flanges?
What is a ring type joint flange?
Ring Type Joint Flange is a method of ensuring leak proof flange connection at high pressures. A metal ring is compressed into a hexagonal groove on the face of the flange to make the seal. This jointing method can be employed on Weld Neck, Slip-on and Blind Flange. The flanges seal when the bolts are tightened and the gasket is compressed into the groove making a metal to metal seal. An RTJ flange usually has a raised face with the groove machined into the face of the flange. The raised face doesn’t serve as a way to contain the pressure.
RTJ Flanges are used for high pressure applications up to pressures as high as 15,000 psi (103 MPa). It is only furnished only on steel or alloy valve bodies and usually need to specified when ordering. The flanges usually come in blind, slip-on, threaded and weld neck.
The benefits of using an RTJ flange and ring is that the gasket is confined to a groove and has two sealing surfaces. The groove assures that the ring centers itself when the bolts are tightened. It also is self actuating meaning that the sealing pressure increases when the process pressure increases.
The disadvantages of using RTJ Flanges is that ring type joint grooves can accumulate dirt or moisture when the flange is open. Since the seal is a metal on metal connection, a small amount of damage on the narrow sealing surface(s) may lead to a leak. Additionally, the grooves and gasket must align properly in order to assemble the flange and obtain a seal. They must stay aligned throughout the operating cycle. This is important if you are flanging up to dissimilar metals like stainless steel to carbon steel flanges.
The Ring Type Joint flanges are typically used in high pressure (Class 600 and higher rating) and/or high temperature services above 800°F (427°C). They have grooves cut into their faces which steel ring gaskets. The flanges seal when tightened bolts compress the gasket between the flanges into the grooves, deforming (or Coining) the gasket to make intimate contact inside the grooves, creating a metal to metal seal.
An RTJ flange may have a raised face with a ring groove machined into it. This raised face does not serve as any part of the sealing means. For RTJ flanges that seal with ring gaskets, the raised faces of the connected and tightened flanges may contact each other. In this case the compressed gasket will not bear additional load beyond the bolt tension, vibration and movement cannot further crush the gasket and lessen the connecting tension.
Design Considerations
When removing the RTJ connection, the flanges must be forcibly separated to release the ring from the groove. Because of this, there needs to be sufficient access for removal of the flanges and removal of the ring.
With the wide acceptance of and significant usage of the spiral wound gasket in high pressure service, RTJ type flanges aren’t as common as raised face flanges. Consideration should be made during the design to ensure that additional rings are available when connections need to be broken.
Ring Type Joint Flanges (RTJ) or Ring Joint Facing Flanges (R-JF):
RTJ flanges have grooves cut into their faces which accept steel Ring Gaskets. RTJ flanges seal when tightened bolts compress the gasket between the flanges into the grooves, deforming (or “Coining”) the gasket to make Intimate Contact inside the grooves, creating a metal to metal seal.
An RTJ flange may have a raised face with a ring groove machined into it.
This raised face does not serve as any part of the sealing means. For RTJ flanges that seal with BX ring gaskets, the raised faces of the connected and tightened flanges may contact each other. In this case the compressed gasket will not bear additional load beyond the bolt tension, vibration and movement cannot further crush the gasket and lessen the connecting tension.
An RTJ flange may have a raised face with a ring groove machined into it. This raised face does not serve as any part of the sealing means.
Standards, Dimensions & Weight
RTJ flanges have grooves cut into their faces which accept steel Ring Gaskets.
- Dimensions of Ring Joint Facings
|
Class 150 NPS |
Groove No. |
Pitch Dia P |
Depth E Note (1) |
Width F |
Radius at bottom R |
| … | R11 | 34.14 | 5.54 | 7.14 | 0.8 |
| … | R12 | 39.67 | 6.35 | 8.74 | 0.8 |
| … | R13 | 42.88 | 6.35 | 8.74 | 0.8 |
| … | R14 | 44.45 | 6.35 | 8.74 | 0.8 |
| 1 | R15 | 47.63 | 6.35 | 8.74 | 0.8 |
| … | R16 | 50.8 | 6.35 | 8.74 | 0.8 |
| 1¼ | R17 | 57.15 | 6.35 | 8.74 | 0.8 |
| … | R18 | 60.33 | 6.35 | 8.74 | 0.8 |
| 1½ | R19 | 65.07 | 6.35 | 8.74 | 0.8 |
| … | R20 | 68.27 | 6.35 | 8.74 | 0.8 |
| … | R21 | 72.23 | 7.92 | 11.91 | 0.8 |
| 2 | R22 | 82.55 | 6.35 | 8.74 | 0.8 |
| … | R23 | 82.55 | 7.92 | 11.91 | 0.8 |
| … | R24 | 95.25 | 7.92 | 11.91 | 0.8 |
| 2½ | R25 | 101.6 | 6.35 | 8.74 | 0.8 |
| … | R26 | 101.6 | 7.92 | 11.91 | 0.8 |
| … | R27 | 107.95 | 7.92 | 11.91 | 0.8 |
| … | R28 | 111.13 | 9.53 | 13.49 | 1.5 |
| 3 | R29 | 114.3 | 6.35 | 8.74 | 0.8 |
| … | R30 | 117.48 | 7.92 | 11.91 | 0.8 |
| … | R31 | 123.83 | 7.92 | 11.91 | 0.8 |
| … | R32 | 127 | 9.53 | 13.49 | 1.5 |
| 3½ | R33 | 131.78 | 6.35 | 8.74 | 0.8 |
| … | R34 | 131.78 | 7.92 | 11.91 | 0.8 |
| … | R35 | 136.53 | 7.92 | 11.91 | 0.8 |
| 4 | R36 | 149.23 | 6.35 | 8.74 | 0.8 |
| … | R37 | 149.23 | 7.92 | 11.91 | 0.8 |
| … | R38 | 157.18 | 11.13 | 16.66 | 1.5 |
| … | R39 | 161.93 | 7.92 | 11.91 | 0.8 |
| 5 | R40 | 171.45 | 6.35 | 8.74 | 0.8 |
| … | R41 | 180.98 | 7.92 | 11.91 | 0.8 |
| … | R42 | 190.5 | 12.7 | 19.84 | 1.5 |
| 6 | R43 | 193.68 | 6.35 | 8.74 | 0.8 |
| … | R44 | 193.68 | 7.92 | 11.91 | 0.8 |
|
Class 150 NPS |
Groove No. |
Pitch Dia P |
Depth E Note (1) |
Width F |
Radius at bottom R |
| … | R45 | 211.12 | 7.92 | 11.91 | 0.8 |
| … | R46 | 211.14 | 9.53 | 13.49 | 1.5 |
| … | R47 | 228.6 | 12.7 | 19.84 | 1.5 |
| 8 | R48 | 247.65 | 6.35 | 8.74 | 0.8 |
| … | R49 | 269.88 | 7.92 | 11.91 | 0.8 |
| … | R50 | 269.88 | 11.13 | 16.66 | 1.5 |
| … | R51 | 279.4 | 14.27 | 23.01 | 1.5 |
| 10 | R52 | 304.8 | 6.35 | 8.74 | 0.8 |
| … | R53 | 323.85 | 7.92 | 11.91 | 0.8 |
| … | R54 | 323.85 | 11.13 | 16.66 | 1.5 |
| … | R55 | 342.9 | 17.48 | 30.18 | 2.4 |
| 12 | R56 | 381 | 6.35 | 8.74 | 0.8 |
| … | R57 | 381 | 7.92 | 11.91 | 0.8 |
| … | R58 | 381 | 14.27 | 23.01 | 1.5 |
| 14 | R59 | 396.88 | 6.35 | 8.74 | 0.8 |
| … | R60 | 406.4 | 17.48 | 33.32 | 2.4 |
| … | R61 | 419.1 | 7.92 | 11.91 | 0.8 |
| … | R62 | 419.1 | 11.13 | 16.66 | 1.5 |
| … | R63 | 419.1 | 15.88 | 26.97 | 2.4 |
| 16 | R64 | 454.03 | 6.35 | 8.74 | 0.8 |
| … | R65 | 469.9 | 7.92 | 11.91 | 0.8 |
| … | R66 | 469.9 | 11.13 | 16.66 | 1.5 |
| … | R67 | 469.9 | 17.48 | 30.18 | 2.4 |
| 18 | R68 | 517.53 | 6.35 | 8.74 | 0.8 |
| … | R69 | 533.4 | 7.92 | 11.91 | 0.8 |
| … | R70 | 533.4 | 12.7 | 19.84 | 1.5 |
| … | R71 | 533.4 | 17.48 | 30.18 | 2.4 |
| 20 | R72 | 558.8 | 6.35 | 8.74 | 0.8 |
| … | R73 | 584.2 | 9.53 | 13.49 | 1.5 |
| … | R74 | 584.2 | 12.7 | 19.84 | 1.5 |
| … | R75 | 584.2 | 17.48 | 33.32 | 2.4 |
| 24 | R76 | 673.1 | 6.35 | 8.74 | 0.8 |
| … | R77 | 692.15 | 11.13 | 16.66 | 1.5 |
| … | R78 | 692.15 | 15.88 | 26.97 | 2.4 |
| … | R79 | 692.15 | 20.62 | 36.53 | 2.4 |
|
Class 150 NPS |
Groove No. |
Pitch Dia P |
Depth E Note (1) |
Width F |
Radius at bottom R |
NOTES:
(1) The height of the raised portion is equal to the depth of the groove dimension, E, but is not subjected to the tolerances for E. Former full-face contour may be used.
(2) For ring joints with lapped flanges in Classes 300 and 600, ring and groove number R30 is used instead of R31.
| Diameter of Raised Portion, K | ||||||
|
Class 150 NPS |
Class 300 NPS |
Class 400 NPS |
Class 600 NPS |
Class 900 NPS |
Class 1500 NPS |
Class 2500 NPS |
| … |
51 1/2 |
… |
51 1/2 |
… | … | … |
| … | … | … | … | … |
60.5 1/2 |
… |
| … |
63.5 3/4 |
… |
63.5 3/4 |
… | … |
65 1/2 |
| … | … | … | … | … |
66.5 3/4 |
… |
|
63.5 1 |
… | … | … | … | … | … |
| … |
70 1 |
… |
70 1 |
… |
71.5 1 |
73 3/4 |
|
73 1¼ |
… | … | … | … | … | … |
| … |
79.5 1¼ |
… |
79.5 1¼ |
… |
81 1¼ |
82.5 1 |
|
82.5 1½ |
… | … | … | … | … | … |
| … |
90.5 1½ |
… |
90.5 1½ |
… |
92 1½ |
… |
| … | … | … | … | … | … |
102 1¼ |
|
102 2 |
… | … | … | … | … | … |
| … |
108 2 |
… |
108 2 |
… | … |
114 1½ |
| … | … | … | … | … |
124 2 |
… |
|
121 2½ |
… | … | … | … | … | … |
| … |
127 2½ |
… |
127 2½ |
… | … |
133 2 |
| … | … | … | … | … |
137 2½ |
… |
|
Class 150 NPS |
Class 300 NPS |
Class 400 NPS |
Class 600 NPS |
Class 900 NPS |
Class 1500 NPS |
Class 2500 NPS |
| … | … | … | … | … | … |
149 2½ |
|
133 3 |
… | … | … | … | … | … |
| … | … | … | … | … | … | … |
| … |
146 3 |
… |
146 3 |
156 3 |
… | … |
| … | … | … | … | … | … |
168 3 |
|
154 3½ |
… | … | … | … | … | … |
| … |
159 3½ |
… |
159 3½ |
… | … | … |
| … | … | … | … | … |
168 3 |
… |
|
171 4 |
… | … | … | … | … | … |
| … |
175 4 |
175 4 |
175 4 |
181 4 |
… | … |
| … | … | … | … | … | … |
203 4 |
| … | … | … | … | … |
194 4 |
… |
|
194 5 |
… | … | … | … | … | … |
| … |
210 5 |
210 5 |
210 5 |
216 5 |
… | … |
| … | … | … | … | … | … |
241 5 |
|
219 6 |
… | … | … | … | … | … |
| … | … | … | … | … |
229 5 |
… |
| … |
241 6 |
241 6 |
241 6 |
241 6 |
… | … |
|
Class 150 NPS |
Class 300 NPS |
Class 400 NPS |
Class 600 NPS |
Class 900 NPS |
Class 1500 NPS |
Class 2500 NPS |
| … | … | … | … | … |
248 6 |
… |
| … | … | … | … | … | … |
279 6 |
|
273 8 |
… | … | … | … | … | … |
| … |
302 8 |
302 8 |
302 8 |
308 8 |
… | … |
| … | … | … | … | … |
318 8 |
… |
| … | … | … | … | … | … |
340 8 |
|
330 10 |
… | … | … | … | … | … |
| … |
356 10 |
356 10 |
356 10 |
362 10 |
… | … |
| … | … | … | … | … |
371 10 |
… |
| … | … | … | … | … | … |
425 10 |
|
406 12 |
… | … | … | … | … | … |
| … |
413 12 |
413 12 |
413 12 |
419 12 |
… | … |
| … | … | … | … | … |
438 12 |
… |
|
425 14 |
… | … | … | … | … | … |
| … | … | … | … | … | … |
495 12 |
| … |
457 14 |
457 14 |
457 14 |
… | … | … |
| … | … | … | … |
467 14 |
… | … |
|
Class 150 NPS |
Class 300 NPS |
Class 400 NPS |
Class 600 NPS |
Class 900 NPS |
Class 1500 NPS |
Class 2500 NPS |
| … | … | … | … | … |
489 14 |
… |
|
483 16 |
… | … | … | … | … | … |
| … |
508 16 |
508 16 |
508 16 |
… | … | … |
| … | … | … | … |
524 16 |
… | … |
| … | … | … | … | … |
546 16 |
… |
|
546 18 |
… | … | … | … | … | … |
| … |
575 18 |
575 18 |
575 18 |
… | … | … |
| … | … | … | … |
594 18 |
… | … |
| … | … | … | … | … |
613 18 |
… |
|
597 20 |
… | … | … | … | … | … |
| … |
635 20 |
635 20 |
635 20 |
… | … | … |
| … | … | … | … |
648 20 |
… | … |
| … | … | … | … | … |
673 20 |
… |
|
711 24 |
… | … | … | … | … | … |
| … |
749 24 |
749 24 |
749 24 |
… | … | … |
| … | … | … | … |
772 24 |
… | … |
| … | … | … | … | … |
794 24 |
… |
|
Class 150 NPS |
Class 300 NPS |
Class 400 NPS |
Class 600 NPS |
Class 900 NPS |
Class 1500 NPS |
Class 2500 NPS |
| Diameter of Raised Portion, K | ||||||
| Approximate Distance Between Flanges, X | ||||||
|
Class 150 NPS |
Class 300 NPS |
Class 400 NPS |
Class 600 NPS |
Class 900 NPS |
Class 1500 NPS |
Class 2500 NPS |
| … |
3 1/2 |
… |
3 1/2 |
… | … | … |
| … | … | … | … | … |
4 1/2 |
… |
| … |
4 3/4 |
… |
4 3/4 |
… | … |
4 1/2 |
| … | … | … | … | … |
4 3/4 |
… |
|
4 1 |
… | … | … | … | … | … |
| … |
4 1 |
… |
4 1 |
… |
4 1 |
4 3/4 |
|
4 1¼ |
… | … | … | … | … | … |
| … |
4 1¼ |
… |
4 1¼ |
… |
4 1¼ |
4 1 |
|
4 1½ |
… | … | … | … | … | … |
| … |
4 1½ |
… |
4 1½ |
… |
4 1½ |
… |
| … | … | … | … | … | … |
3 1¼ |
|
4 2 |
… | … | … | … | … | … |
| … |
6 2 |
… |
5 2 |
… | … |
3 1½ |
| … | … | … | … | … |
3 2 |
… |
|
4 2½ |
… | … | … | … | … | … |
| … |
6 2½ |
… |
5 2½ |
… | … |
3 2 |
| … | … | … | … | … |
3 2½ |
… |
|
Class 150 NPS |
Class 300 NPS |
Class 400 NPS |
Class 600 NPS |
Class 900 NPS |
Class 1500 NPS |
Class 2500 NPS |
| … | … | … | … | … | … |
3 2½ |
|
4 3 |
… | … | … | … | … | … |
| … | … | … | … | … | … | … |
| … |
6 3 |
… |
5 3 |
4 3 |
… | … |
| … | … | … | … | … | … |
3 3 |
|
4 3½ |
… | … | … | … | … | … |
| … |
6 3½ |
… |
5 3½ |
… | … | … |
| … | … | … | … | … |
3 3 |
… |
|
4 4 |
… | … | … | … | … | … |
| … |
6 4 |
6 4 |
5 4 |
4 4 |
… | … |
| … | … | … | … | … | … |
4 4 |
| … | … | … | … | … |
3 4 |
… |
|
4 5 |
… | … | … | … | … | … |
| … |
6 5 |
6 5 |
5 5 |
4 5 |
… | … |
| … | … | … | … | … | … |
4 5 |
|
4 6 |
… | … | … | … | … | … |
| … | … | … | … | … |
3 5 |
… |
| … |
6 6 |
6 6 |
5 6 |
4 6 |
… | … |
|
Class 150 NPS |
Class 300 NPS |
Class 400 NPS |
Class 600 NPS |
Class 900 NPS |
Class 1500 NPS |
Class 2500 NPS |
| … | … | … | … | … |
3 6 |
… |
| … | … | … | … | … | … |
4 6 |
|
4 8 |
… | … | … | … | … | … |
| … |
6 8 |
6 8 |
5 8 |
4 8 |
… | … |
| … | … | … | … | … |
4 8 |
… |
| … | … | … | … | … | … |
5 8 |
|
4 10 |
… | … | … | … | … | … |
| … |
6 10 |
6 10 |
5 10 |
4 10 |
… | … |
| … | … | … | … | … |
4 10 |
… |
| … | … | … | … | … | … |
6 10 |
|
4 12 |
… | … | … | … | … | … |
| … |
6 12 |
6 12 |
5 12 |
4 12 |
… | … |
| … | … | … | … | … |
5 12 |
… |
|
3 14 |
… | … | … | … | … | … |
| … | … | … | … | … | … |
8 12 |
| … |
6 14 |
6 14 |
5 14 |
… | … | … |
| … | … | … | … |
4 14 |
… | … |
|
Class 150 NPS |
Class 300 NPS |
Class 400 NPS |
Class 600 NPS |
Class 900 NPS |
Class 1500 NPS |
Class 2500 NPS |
| … | … | … | … | … |
6 14 |
… |
|
3 16 |
… | … | … | … | … | … |
| … |
6 16 |
6 16 |
5 16 |
… | … | … |
| … | … | … | … |
4 16 |
… | … |
| … | … | … | … | … |
8 16 |
… |
|
3 18 |
… | … | … | … | … | … |
| … |
6 18 |
6 18 |
5 18 |
… | … | … |
| … | … | … | … |
5 18 |
… | … |
| … | … | … | … | … |
8 18 |
… |
|
3 20 |
… | … | … | … | … | … |
| … |
6 20 |
6 20 |
5 20 |
… | … | … |
| … | … | … | … |
5 20 |
… | … |
| … | … | … | … | … |
10 20 |
… |
|
3 24 |
… | … | … | … | … | … |
| … |
6 24 |
6 24 |
6 24 |
… | … | … |
| … | … | … | … |
6 24 |
… | … |
| … | … | … | … | … |
11 24 |
… |
|
Class 150 NPS |
Class 300 NPS |
Class 400 NPS |
Class 600 NPS |
Class 900 NPS |
Class 1500 NPS |
Class 2500 NPS |
| Approximate Distance Between Flanges, X | ||||||
GENERAL NOTES:
(a) Dimensions are in millimeters unless otherwise indicated.
(b) Use Class 600 sizes NPS 1/2 to NPS 3½ for Class 400.
(c) Use Class 1500 in sizes NPS 1/2 to NPS 2½ for Class 900.
(d) Ring joint gasket materials shall conform to ASME B16.20.
(e) The edge (periphery) of each ring joint flange shall be marked with the letter R and the corresponding ring groove number.
NOTES:
(1) The height of the raised portion is equal to the depth of the groove dimension, E, but is not subjected to the tolerances for E. Former full-face contour may be used.
(2) For ring joints with lapped flanges in Classes 300 and 600, ring and groove number R30 is used instead of R31.
TOLERANCES:
E (depth) +0.4 -0.0, F (width) ±0.2, P (pitch diameter) ±0.13, R (radius at bottom)≤ 2 + 0.8 -0.0, > 2 ± 0.8,
23° (angle) ± 1/2°
RTJ flanges seal when tightened bolts compress the gasket between the flanges into the grooves, deforming (or “Coining”) the gasket to make Intimate Contact inside the grooves, creating a metal to metal seal.
Ring Type Joint gaskets
Ring Type Joint gaskets are metallic sealing rings, suitable for high-pressure and high-temperature applications. They are always applied to special, accompanying flanges which ensure good, reliable sealing with the correct choice of profiles and material.
Specifications of Ring Type Joint Flange:
An RTJ flange may have a raised face with a ring groove machined into it. This raised face does not serve as any part of the sealing means. For RTJ flanges that seal with BX ring gaskets, the raised faces of the connected and tightened flanges may contact each other. 
In this case the already coined gasket will not bear additional load beyond the bolt tension, vibration and movement cannot further crush the gasket and lessen the connecting tension.
Size: 1/2” to 60”, DN 12mm to DN 1500mm
Pressure class: Class 150 to Class 2,500, PN 2.5 to PN 250
Standards: ANSI, MSS, API, AWWA, DIN, JIS, BS and GB.
Facing: RF / RTJ>
Material:
Cabon steel: A105, A350 LF2
Stainless steel: A182 F304/F304L/F316/F316L/F321
Alloy steel: F11, F12
Packing: plywood case and plywood pallet
Source: China Ring Type Joint Flanges Manufacturer – Yaang Pipe Industry Co., Limited (www.steeljrv.com)
(Yaang Pipe Industry is a leading manufacturer and supplier of nickel alloy and stainless steel products, including Super Duplex Stainless Steel Flanges, Stainless Steel Flanges, Stainless Steel Pipe Fittings, Stainless Steel Pipe. Yaang products are widely used in Shipbuilding, Nuclear power, Marine engineering, Petroleum, Chemical, Mining, Sewage treatment, Natural gas and Pressure vessels and other industries.)
If you want to have more information about the article or you want to share your opinion with us, contact us at sales@steeljrv.com
Please notice that you might be interested in the other technical articles we’ve published:
• HOW TO GET HIGH QUALITY BLIND FLANGES
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• Development trend of high pressure pipe fittings
• How to get high quality flanges
• How to get high quality pipe fittings
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• HOW TO GET HIGH QUALITY STEEL PIPES
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References:
- https://www.woodcousa.com/q_a-r_29.htm
- http://www.piping-designer.com/index.php/disciplines/mechanical/83-stationary-equipment/pipe-flanges/2012-ring-type-joint-flange
- http://www.wermac.org/flanges/flanges_raised-face_flat-face_ring-type-joint.html
- http://www.wermac.org/flanges/dimensions_ring-joint-facings_flanges_asme-b16.5.html
- https://www.yaang.com
