API Standard Update

For information purposes only:

The new standard does not comply with ISO 10423:2009 (modified)
Specification name changed from Specification for Wellhead and Christmas Tree Equipment (Edition 20) to Specification for Wellhead and Tree Equipment (Edition 21)
Quality requirements are now grouped by specific activity and not by PSL, making it easier to determine the specific requirements for all PSLs in one location and not spread throughout the document
PSL 3G is not part of the licensing programme. A supplemental designation of PSL 3G shall apply to PSL 3 products that have satisfied the PSL 3 requirements in addition to the requirements of gas testing. (Not an official marking, but 3G can be marked if the product is GAS tested)
“Room Temperature” replaced with Temperature between 4 °C and 50 °C (between 40 °F and 120 °F)
Certificate of Compliance replaced with Certificate of Conformance
NL – NO LIMIT removed from the specification as NACE MR 0175 addressed the H2S limits for materials
Heat treatment requirements now normative
API 6X introduced for design activities
New chapters Bolting, Pressure Boundary, Factory Acceptance Test and Records added
Table 3 for material requirements now cover stainless steel and CRA for all the material classes
Table 4 calls for applicability of product specification levels
Table 9 for impact requirements consider PSL1, impact values for longitudinal direction added and transverse direction testing covers wrought, cast and welder qualification
Table 12 phosphorous and sulphur concentration added for PSL1 and values restricted for PSL4
Required minimum 20E and 20F BSL for bolting
Table 15 API 20E, BSL requirements added for closure bolting
Table 30 covers Factory Acceptance Testing (FAT) for pressure tested / non-pressure tested equipment
Table 31 specifies equipment wise and PSL wise Factory Acceptance Testing (FAT)
Annex F, G, K & M use same annex numbers in edition 20 & edition 21
Annex J (Weld‐neck Flanges) and L (Segmented Flanges), new in Edition 21
Annex E, H, I, N, O & J in Edition 20 was not part of Edition 21
Repair and remanufacture of 6A (Section 11 & Annex J of Ed.20) products not covered in Edition 21, instead a new specification API 6AR “Repair and Remanufacture of Wellhead and Tree Equipment” introduced
The casing and tubing hanger’s product line is better defined for slip and mandrel hangers, two separate products. So, in effect, there will be three new products
Fluid sampling devices removed
Integration of tubing head adapter requirements into overall head requirements for a more integrated product
Required minimum PSL depending on the pressure rating and material class. Revised PSL 4 to target critical service equipment
Removal of PR1 from design validation annex
Addition of pressure boundary qualification requirements
Creation of a new section on records and records control
Factory Acceptance Testing (FAT) removed from the quality section; section reorganised, and requirements presented in a more logical order
Marking requirements now target specific products and not product families to better target specific marking needs
Operating torque to be measured for PSL 3 valves while operating under full differential to confirm that the values fall within the manufacturer’s specified requirements for manual and actuated valves

Minimum product specification level (PSL) for working pressure:
Material Class	13.8 MPa (2000 PSI)	20.7 MPa (3000 PSI)	34.5 MPa (5000 PSI)	69.0 MPa (10,000 PSI)	103.5 MPa (15,000 PSI)	138.0 MPa (20,000 PSI)
AA, BB, CC	PSL 1	PSL 1	PSL 1	PSL 2	PSL 2	PSL 3
DD, EE, FF	PSL 1	PSL 1	PSL 1	PSL 2	PSL 3	PSL 3
HH, ZZ	PSL 3	PSL 3	PSL 3	PSL 3	PSL 3	PSL 4

Information on API 6A standard stud length and ring gasket

SIZE	PSI	GASKET SIZE	QTY.	STUD DIA	THREAD	FULL THREAD STUD LENGTH	TAP END STUD
SIZE	PSI	GASKET SIZE	QTY.	STUD DIA	THREAD	FULL THREAD STUD LENGTH	TAP END LENGTH	NUT END LENGTH	TOTAL LENGTH
1-13/16″	10K	BX-151	8	3/4	10 UNC	5.500”	0.900″	1.875″	3.750″
1-13/16″	15K	BX-151	8	7/8	9 UNC	6.000″	1.042″	2.188″	4.125″
1-13/16″	20K	BX-151	8	1	8 UNC	7.750″	1.188″	2.500″	5.125″
2- 1/16″	2K	RX-23	8	5/8	11 UNC	5.000″	0.761″	1.563″	3.625″
2- 1/16″	3K	RX-24	8	7/8	9 UNC	6.500″	1.042″	2.188″	4.625″
2- 1/16″	5K	RX-24	8	7/8	9 UNC	6.500″	1.042″	2.188″	4.625″
2- 1/16″	10K	BX-152	8	3/4	10 UNC	5.500″	0.900″	1.875″	3.875″
2- 1/16″	15K	BX-152	8	7/8	9 UNC	6.500″	1.042″	2.188″	4.375″
2- 1/16″	20K	BX-152	8	1 1/8	8 UN	8.500″	1.313″	2.813″	5.750″
2- 9/16″	2K	RX-26	8	3/4	10 UNC	5.500″	0.900″	1.875″	4.000″
2- 9/16″	3K	RX-27	8	1	8 UNC	7.000″	1.188″	2.500″	5.125″
2- 9/16″	5K	RX-27	8	1	8 UNC	7.000″	1.188″	2.500″	5.125″
2- 9/16″	10K	BX-153	8	7/8	9 UNC	6.500″	1.042″	2.188″	4.375″
2- 9/16″	15K	BX-153	8	1	8 UN	7.250″	1.188″	2.500″	4.875″
2- 9/16″	20K	BX-153	8	1 1/4	8 UN	9.500″	1.438″	3.125″	6.250″
3- 1/8″	2K	RX-31	8	3/4	10 UNC	5.750″	0.900″	1.875″	4.125″
3- 1/8″	3K	RX-31	8	7/8	9 UNC	6.500″	1.042″	2.188″	4.625″
3- 1/8″	5K	RX-35	8	1 1/8	8 UN	7.750″	1.313″	2.813″	5.625″
3- 1/16″	10K	BX-154	8	1	8 UNC	7.250″	1.188″	2.500″	5.000″
3- 1/16″	15K	BX-154	8	1 1/8	8 UN	8.000″	1.313″	2.813″	5.500″
3- 1/16″	20K	BX-154	8	1 3/8	8 UN	10.250″	1.563″	3.438″	6.750″
4- 1/16″	2K	RX-37	8	7/8	9 UNC	6.500″	1.042″	2.188″	4.625″
4- 1/16″	3K	RX-37	8	1 1/8	8 UN	7.500″	1.313″	2.813″	5.500″
4- 1/16″	5K	RX-39	8	1 1/4	8 UN	8.500″	1.438″	3.125″	6.125″
4- 1/16″	10K	BX-155	8	1 1/8	8 UN	8.500″	1.313″	2.813″	5.750″
4- 1/16″	15K	BX-155	8	1 3/8	8 UN	9.750″	1.563″	3.438″	6.500″
4- 1/16″	20K	BX-155	8	1 3/4	8 UN	12.500″	1.938″	4.375″	8.375″
5- 1/8″	2K	RX-41	8	1	8 UNC	7.250″	1.188″	2.500″	5.250″
5- 1/8″	3K	RX-41	8	1 1/4	8 UN	8.250″	1.438″	3.125″	6.000″
5- 1/8″	5K	RX-44	8	1 1/2	8 UN	10.500″	1.688″	3.750″	7.375″
5- 1/8″	10K	BX-169	12	1 1/8	8 UN	9.250″	1.313″	2.813″	6.000″
5- 1/8″	15K	BX-169	12	1-1/2	8 UN	11.500″	1.688″	3.750″	7.625″
7- 1/16″	2K	RX-45	12	1	8 UNC	7.500″	1.188″	2.500″	5.375″
7- 1/16″	3K	RX-45	12	1 1/8	8 UN	8.500″	1.313″	2.813″	5.875″
7- 1/16″	5K	RX-46	12	1 3/8	8 UN	11.250″	1.563″	3.438″	7.500″
7- 1/16″	10K	BX-156	12	1 1/2	8 UN	11.750″	1.688″	3.750″	7.750″
7- 1/16″	15K	BX-156	16	1 1/2	8 UN	13.000″	1.688″	3.750″	8.375″
7- 1/16″	20K	BX-156	16	2	8 UN	17.750″	2.188″	5.000″	11.125″
9″	2K	RX-49	12	1 1/8	8 UN	8.500″	1.313″	2.813″	5.875″
9″	3K	RX-49	12	1 3/8	8 UN	9.500″	1.563″	3.438″	6.750″
9″	5K	RX-50	12	1 5/8	8 UN	12.500″	1.813″	4.063″	8.500″
9″	10K	BX-157	16	1 1/2	8 UN	13.500″	1.688″	3.750″	8.500″
9″	15K	BX-157	16	1 7/8	8 UN	16.000″	2.063″	4.688″	10.125″
9″	20K	BX-157	16	2 1/2	8 UN	21.750″	2.688″	6.250″	13.750″
11″	2K	RX-53	16	1 1/4	8 UN	9.250″	1.438″	3.125″	6.500″
11″	3K	RX-53	16	1 3/8	8 UN	10.000″	1.563″	3.438″	7.000″
11″	5K	RX-54	12	1 7/8	8 UN	14.250″	2.063″	4.688″	9.625″
11″	10K	BX-158	16	1 3/4	8 UN	15.250″	1.938″	4.375″	9.750″
11″	15K	BX-158	20	2	8 UN	19.500″	2.188″	5.000″	12.000″
11″	20K	BX-158	16	2 3/4	8 UN	23.750″	2.938″	6.875″	15.000″
13- 5/8″	2K	RX-57	20	1 1/4	8 UN	9.500″	1.438″	3.125″	6.625″
13- 5/8″	3K	RX-57	20	1 3/8	8 UN	10.750″	1.563″	3.438″	7.375″
13- 5/8″	5K	BX-160	16	1 5/8	8 UN	12.750″	1.813″	4.063″	8.375″
13- 5/8″	10K	BX-159	20	1 7/8	8 UN	17.750″	2.063″	4.688″	11.000″
13- 5/8″	15K	BX-159	20	2 1/4	8 UN	21.250″	2.438″	5.625″	13.250″
13- 5/8″	20K	BX-159	20	3	8 UN	29.750″	3.188″	7.500″	18.125″
16- 3/4″	2K	RX-65	20	1 1/2	8 UN	10.750″	1.688″	3.750″	7.500″
16- 3/4″	3K	RX-66	20	1 5/8	8 UN	12.250″	1.813″	4.063″	8.375″
16- 3/4″	5K	BX-162	16	1 7/8	8 UN	14.750″	2.063″	4.688″	9.500″
16- 3/4″	10K	BX-162	24	1 7/8	8 UN	17.750″	2.063″	4.688″	11.000″
18- 3/4″	5K	BX-163	20	2	8 UN	17.750′	2.188″	5.000″	11.250″
18- 3/4″	10K	BX-164	24	2 1/4	8 UN	22.750″	2.438″	5.625″	14.000″
18- 3/4″	15K	BX-164	20	3	8 UN	26.750″	3.188″	7.500″	16.750″
21- 1/4″	2K	RX-73	24	1 5/8	8 UN	12.250″	1.813″	4.063″	8.375″
20-3/4″	3K	RX-74	20	2	8 UN	15.000″	2.188″	5.000″	10.125″
21- 1/4″	5K	BX-165	24	2	8 UN	19.000″	2.188″	5.000″	11.750″
21- 1/4″	10K	BX-166	24	2 1/2	8 UN	24.750″	2.688”	6.250″	15.125″
26- 3/4″	2K	BX-167	20	1 3/4	8 UN	14.250″	1.938″	4.375″	9.125″
26- 3/4″	3K	BX-168	24	2	8 UN	17.500″	2.188″	5.000″	11.000″
29-1/2″	500	R-95	28	1 3/4	8 UN	12.500″	1.938″	4.375″	8.250″
30″	2K	BX-303	32	1 5/8	8 UN	14.500″	1.813″	4.063″	9.250″
30″	3K	BX-303	32	1 7/8	8 UN	17.750″	2.063″	4.688″	11.000″

For information purposes only:

This specification does not apply to field use or field testing of drill through equipment
Table 2 in “Rated working pressure”, 3 new pressure ratings 1,000, 25,000 & 30,000 added
Table 3 for “Temperature rating” modified from 3 to 6 ratings with elevated temperatures
Spacer spool added to this edition along with drilling spool
Clamp modified as Hub Clamp End Connector
Repair and remanufacture of 16A equipment are covered in API 16AR, Standard for Repair and Remanufacturing of Drill-through Equipment
Product Description Code (PDC) now covers FFF for Product Requirements

API 16A Pressure Ratings:

MPa	6.9	13.8	20.7	34.5	69.0	103.4	138.0	172.7	206.8
PSI	1,000	2,000	3,000	5,000	10,000	15,000	20,000	25,000	30,000

API 16A Temperature Ratings:

STANDARD TEMPERATURE RANGE
T-75/250	- 59°C to 121°C	- 75°F to 250°F
T-20/250	- 29°C to 121°C	- 20°F to 250°F
T-0/250	- 29°C to 121°C	0°F to 250°F
ELEVATED TEMPERATURE RANGE
T-75/350	- 59°C to 177°C	- 75°F to 350°F
T-20/350	- 29°C to 177°C	- 20°F to 350°F
T-0/350	- 18°C to 177°C	0°F to 350°F

API 16A Bolting Requirements:

API 20E	Material	Land	Offshore
Pressure-controlling bolting	Alloy steel and carbon steel	API 20E BSL-1	API 20E BSL-2
Closure bolting		API 20E BSL-1	API 20E BSL-3
Pressure-retaining bolting		API 20E BSL-2	API 20E BSL-3
Utility bolting		Mfg. Spec.	Mfg. Spec.
API 20F	Material	Land	Offshore
Pressure-controlling bolting	Stainless steel and CRA	API 20F BSL-2	API 20F BSL-2
Closure bolting		API 20F BSL-2	API 20F BSL-3
Pressure-retaining bolting		API 20F BSL-2	API 20F BSL-3
Utility bolting		Mfg. Spec.	Mfg. Spec.

Pressure-controlling bolting:

Bolting used to assemble or join pressure-controlling parts.

Example: Bolting on ram, seat, or seal retainer bolting, shear ram blade bolting.

Closure bolting:

Bolting used to assemble or join wellbore pressure-containing parts, including end and outlet connections.

Example: Flange bolting, bonnet bolting and end-connection bolting on BOPs, ram door bolting, and hub clamp bolting.

Pressure-retaining bolting:

Bolting used to assemble or join pressure-retaining parts whose failure would result in a release of wellbore fluid to the environment.

Example: Studs and nuts on top of a hydraulic connector, and clamp bolts.

Utility bolting:

All bolting that is required to mount equipment and accessories to the drill through equipment that is not closure bolting, pressure retaining, or pressure controlling.

Example: bolting on lifting eyes, pad eyes (non-welded), wear bushing, nameplate, clamps for tubing, guards.

API 6A

API 16A

API 5CT

API Q1

API 7-1

API 16-C

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