Carbon Steel Pipe Cap

Carbon steel pipe cap is also known as head cap which is used to weld or install on the male thread of end of pipes for blocking the pipelines. It has same function as plug and blind flange.

Steel pipelines includes pipes, fittings, flanges, gaskets, valves, bolts and nuts. It is important to select proper piping material to ensure system safety and durability at appropriate cost.

We can produce pipe fittings & flanges in customized size as per customer required. Usually stock the dimensions in accordance with standards of ASME B16.9, B16.5, B16.11 & BS3799.  Our goods are good for waterproof the connections to avoid leakage, and laso can work high pressure and temperature situation.

Main Functions

Closing and Sealing: The primary function is to permanently or temporarily close the open end of a pipeline to ensure the integrity and tightness of the piping system. This is crucial for pipelines conveying liquid or gaseous media, and can effectively prevent leakage.

Safety: Closing off the end of a pipe prevents foreign objects from entering the interior of the pipe and protects equipment and fluids from contamination. In some cases, it can also prevent accidental contact with hazardous media in the pipeline.

Pressure Testing: When a piping system is being tested for water or air pressure, the cap is used to enclose the piping so that the inside of the system can withstand the test pressure.

Future Expansion: Some piping systems are designed to allow for future expansion connections, which are closed with a cap and then removed and connected to the new piping when needed.

Types of Carbon Steel Pipe Cap

• Carbon Steel Butt Weld Cap
• Stainless Steel Socket Weld Cap
• Carbon Steel Threaded Pipe Cap

ASME B16.9 End Cap Dimensions

ANSI / ASME B16.9 Standard covers overall dimensions, tolerances, ratings, testing, and markings for wrought factory-made butt-welding fittings in sizes NPS 1/2 through 48 (DN 15 through 1200) and thickness Schedule 10, 20, 30, STD, 40, 60, XS, 80, 100,120,140,160, XXS.

Buttwelding Cap Drawing

ASME B16.11 Socket Weld Cap Dimensions

ANSI / ASME B16.11 Standard covers ratings, dimensions, tolerances, marking and material requirements for socket-welding and threaded forged fittings. These fittings are designated as Class 2000, 3000, and 6000 for threaded pipe fittings and Class 3000, 6000, and 9000 for socket weld fittings. B16.11 is to be used in conjunction with equipment described in other volumes of the ASME B16 series of standards as well as with other ASME standards, such as the Boiler and Pressure Vessel Code and the B31 Piping Codes.

Socket Weld Cap Drawing

DN	NPS	B	C						J	K
			3000		6000		9000			3000	6000	9000
			ave	min	ave	min	ave	min
6	1/8	10.9	3.18	3.18	3.96	3.43			9.5	4.8	6.4
8	1/4	14.3	3.78	3.3	4.6	4.01			9.5	4.8	6.4
10	3/8	17.7	4.01	3.5	5.03	4.37			9.5	4.8	6.4
15	1/2	21.9	4.67	4.09	5.97	5.18	9.53	8.18	9.5	6.4	7.9	11.2
20	3/4	27.3	4.9	4.27	6.96	6.04	9.78	8.56	12.5	6.4	7.9	12.7
25	1	34	5.69	4.98	7.92	6.93	11.38	9.96	12.5	9.6	11.2	14.2
32	1 1/4	42.8	6.07	5.28	7.92	6.93	12.14	10.62	12.5	9.6	11.2	14.2
40	1 1/2	48.9	6.35	5.54	8.92	7.8	12.7	11.12	12.5	11.2	12.7	15.7
50	2	61.2	6.93	6.04	10.92	9.5	13.84	12.12	16	12.7	15.7	19
65	2 1/2	73.9	8.76	7.62					16	15.7	19
80	3	89.9	9.52	8.3					16	19	22.4
100	4	115.5	10.69	9.35					19	22.4	28.4

Threaded Cap Drawing

Threaded Pipe Cap Dimensions

DN	NPS	P		D		G		L5	L2
		3000	6000	3000	6000	3000	6000
6	1/8	19	–	16	22	4.8	–	6.4	6.7
8	1/4	25	27	19	25	4.8	6.4	8.1	10.2
10	3/8	25	27	22	32	4.8	6.4	9.1	10.4
15	1/2	32	33	28	38	6.4	7.9	10.9	13.6
20	3/4	37	38	35	44	6.4	7.9	12.7	13.9
25	1	41	43	44	57	9.7	11.2	14.7	17.3
32	1 1/4	44	46	57	64	9.7	11.2	17	18
40	1 1/2	44	48	64	76	11.2	12.7	17.8	18.4
50	2	48	51	76	92	12.7	15.7	19	19.2
65	2 1/2	60	64	92	108	15.7	19	23.6	28.9
80	3	65	68	108	127	19	22.4	25.9	30.5
100	4	68	75	140	159	22.4	28.4	27.7	33

Forged Carbon Steel Cap

Forged carbon steel fittings caps are made from steel rod by forging, there are two connection types that socket weld and threaded.

The orignal material material grades :

ASTM A105

ASTM A350 LF2 / LF3

A694 F42, F46, F50, F52, F56, F60, F65, F70.

The surface coating can be hot dip galvanized and cold galvanized,  the hot dip galvanizing have long life but not pretty, while cold galvanizing oppositly.

Chemical Composition

Grade	C	Mn	P	S	Si	Ni	Cr	Mo	Cu	N	V
ASTM A105	0.35	0.6-1.05	0.035	0.04	0.1-0.35	0.4	0.3	0.12	0.4	–	0.08
A350 LF2	0.3	0.6-1.35	0.035	0.04	0.15-0.30	0.4	0.3	0.12	0.4	0.02	0.08
A350 LF3	0.2	0.9	0.035	0.04	0.2-0.35	3.3-3.7	0.3	0.12	0.4	0.02	0.03
A694 F42	0.3	1.6	0.025	0.025	0.15-0.35	–	–	–	–	–	–
A694 F46	0.3	1.6	0.025	0.025	0.15-0.35	–	–	–	–	–	–
A694 F50	0.3	1.6	0.025	0.025	0.15-0.35	–	–	–	–	–	–
A694 F52	0.3	1.6	0.025	0.025	0.15-0.35	–	–	–	–	–	–
A694 F56	0.3	1.6	0.025	0.025	0.15-0.35	–	–	–	–	–	–
A694 F60	0.3	1.6	0.025	0.025	0.15-0.35	–	–	–	–	–	–
A694 F65	0.3	1.6	0.025	0.025	0.15-0.35	–	–	–	–	–	–
A694 F70	0.3	1.6	0.025	0.025	0.15-0.35	–	–	–	–	–	–

Mechnical Properties

Grade	Y.S (Mpa)	T.S (Mpa)	EL (%)
ASTM A105	250	485	22
A350 LF2	205	415-585	22
A350 LF3	250	485-655	22
A694 F42	290	415	20
A694 F46	315	415	20
A694 F50	345	440	20
A694 F52	360	455	20
A694 F56	385	470	20
A694 F60	415	515	20
A694 F65	450	530	20
A694 F70	485	565	18

Carbon Steel Buttwelding Cap

Carbon steel butt weld pipe caps are made from steel plate. It connects steel pipe by welding and the diameter size of pipe cap is larger than forged steel cap.

There are many grades such as ：

ASTM A234 WPB / WPC

WPL6 / 3 / 9

A860 WPHY 42 / 46 / 52 / 60 / 65 /70.

Usually we use coating of primer and galvaning on buttweld cap against rust. The primer could be normal, FBE, EPOXY RESIN, while the galvaning is hot dip type.

Chemical Composition

Grade	C	Mn	P	S	Si	Ni	Cr	Mo	Cu	Ti	V
A234 WPB	0.3	0.29-1.06	0.05	0.058	0.1 min	0.4	0.4	0.15	0.4	–	0.08
A234 WPC	0.35	0.29-1.06	0.05	0.058	0.1 min	0.4	0.4	0.15	0.4	–	0.08
A420 WPL6	0.3	0.5-1.35	0.035	0.04	0.15-0.4	0.4	0.3	0.12	0.4	–	0.08
A420 WPL3	0.2	0.31-0.64	0.05	0.05	0.13-0.37	3.2-3.8	–	–	–	–	–
A420 WPL9	0.2	0.4-1.06	0.03	0.03	–	1.6-2.24	–	–	0.75-1.25	–	–
A860 WPHY42	0.2	1-1.45	0.03	0.01	0.15-0.4	0.5	0.3	0.25	0.35	0.05	0.1
A860 WPHY46	0.2	1-1.45	0.03	0.01	0.15-0.4	0.5	0.3	0.25	0.35	0.05	0.1
A860 WPHY52	0.2	1-1.45	0.03	0.01	0.15-0.4	0.5	0.3	0.25	0.35	0.05	0.1
A860 WPHY60	0.2	1-1.45	0.03	0.01	0.15-0.4	0.5	0.3	0.25	0.35	0.05	0.1
A860 WPHY65	0.2	1-1.45	0.03	0.01	0.15-0.4	0.5	0.3	0.25	0.35	0.05	0.1
A860 WPHY70	0.2	1-1.45	0.03	0.01	0.15-0.4	0.5	0.3	0.25	0.35	0.05	0.1

Mechnical Properties

Grade	Y.S (Mpa)	T.S (Mpa)	EL (%)
A234 WPB	240	415-655	22
A234 WPC	275	485-655	22
A420 WPL6	240	415-655	22
A420 WPL3	250	450-620	22
A420 WPL9	315	435-610	20
A860 WPHY42	290	415	20
A860 WPHY46	315	415	20
A860 WPHY52	360	455	20
A860 WPHY60	415	515	20
A860 WPHY65	450	530	20
A860 WPHY70	485	565	18

Areas of Application

Carbon Steel Pipe Caps are widely used in industry due to their cost-effectiveness, moderate strength and good weldability:

Oil & Gas: Used for end closure of piping systems, such as temporary plugging, permanent end closure or pressure testing.

Chemical and petrochemical: piping systems conveying all kinds of chemicals need reliable seals to prevent leakage.

Power: Water, steam and fuel piping in power plants.

Building and Structural: End caps used to enclose piping or as structural support in construction projects.

WATER TREATMENT: Water supply and drainage systems, sewage treatment plants, etc.