Cap
- Our pipe caps are hot forged or pressed from premium carbon steel, alloy steel and stainless steel, featuring excellent pressure bearing and anti-corrosion capacity. Available in elliptical, hemispherical, flat and threaded types. Precision CNC machining ensures smooth inner cavity and reliable end sealing. Strict full-process quality control guarantees accurate dimensions and stable mechanical performance. Widely used in oil & gas, petrochemical, power, marine, water treatment and construction piping systems.
Certified:
All caps are equipped with complete factory test reports covering chemical composition, mechanical properties, dimensional inspection, NDT and hydrostatic testing. Products comply with ISO, ASTM, ASME, DIN, EN and JIS standards. Material mill certificates EN 10204 3.1 / 3.2, third-party inspection certificates and full shipping documents can be provided on request to realize full quality traceability for global industrial buyers.
Application:
Caps are essential pipe end sealing fittings for all industrial piping systems, used to permanently block pipe terminals for maintenance, expansion or shutdown. In oil & gas transmission, they seal idle pipe ends under high temperature and pressure to prevent medium leakage. Petrochemical plants adopt anti-corrosion caps to close pipeline terminals connected to reactors, storage tanks and corrosive medium conveying pipelines. Thermal and nuclear power stations use high-temperature resistant elliptical caps for boiler and steam pipeline end sealing to withstand long-term severe working conditions. Marine and offshore engineering utilizes seawater corrosion resistant caps for fuel, ballast and fire-fighting pipe terminals on vessels and platforms. Water treatment and desalination projects match large-size caps for pump and filter pipeline temporary blocking. In construction, caps are widely installed in HVAC, fire protection and plumbing systems for later pipeline expansion. Sanitary stainless steel caps are used in food and pharmaceutical production lines to meet high hygiene standards without medium contamination.
Specification:
1. Product Specification
Parameter | Detailed Specification |
Product Type | Elliptical Cap, Hemispherical Cap, Flat Cap, Threaded Cap, Seamless Cap, Welded Cap |
Size Range | 1/2" – 60" (DN15 – DN1500), customized sizes available |
Pressure Rating | Class 150, 300, 600, 900, 1500, 2500 (PN20 – PN420) |
End Connection | BW Butt Weld, SW Socket Weld, NPT Threaded |
Manufacturing Process | Hot Press Forming, Hot Forging, Heat Treatment, CNC Machining |
Applicable Standards | ASME B16.9, ASME B16.11, MSS SP-75, DIN 2617, EN 10253, JIS B2314, GOST 17379, ISO 3419 |
Material Grades | Carbon Steel: A234 WPB, WP12, WP22 / Stainless Steel: 304, 304L, 316, 316L, 321, 904L / Alloy Steel: A234 WP5, WP9, WP11, WP91 |
2. Chemical Composition
Grade | C | Si | Mn | P | S | Cr | Ni | Mo |
A234 WPB | ≤0.30 | ≤0.35 | 0.29–1.06 | ≤0.035 | ≤0.035 | ≤0.40 | ≤0.40 | — |
WP11 | 0.05–0.15 | 0.50–1.00 | 0.30–0.60 | ≤0.030 | ≤0.030 | 1.00–1.50 | — | 0.44–0.65 |
WP22 | 0.05–0.15 | ≤0.50 | 0.30–0.60 | ≤0.030 | ≤0.030 | 2.00–2.50 | — | 0.87–1.13 |
304 | ≤0.08 | ≤0.75 | ≤2.00 | ≤0.045 | ≤0.030 | 18.0–20.0 | 8.00–10.5 | — |
304L | ≤0.03 | ≤0.75 | ≤2.00 | ≤0.045 | ≤0.030 | 18.0–20.0 | 8.00–12.0 | — |
316 | ≤0.08 | ≤0.75 | ≤2.00 | ≤0.045 | ≤0.030 | 16.0–18.0 | 10.0–14.0 | 2.00–3.00 |
316L | ≤0.03 | ≤0.75 | ≤2.00 | ≤0.045 | ≤0.030 | 16.0–18.0 | 10.0–14.0 | 2.00–3.00 |
Standard:
Classification | Grade | Applicable Standard | Key Chemical Composition (wt%) | Key Mechanical Properties (Room Temperature) |
Carbon Steel | A234 WPB | ASTM A234 | C≤0.30, Mn 0.29~1.06, S≤0.035, P≤0.035 | TS≥415MPa, YS≥205MPa, EL≥22%, H≤156HB |
Low Alloy Steel | WP11 | ASTM A234 | C 0.05~0.15, Cr 1.00~1.50, Mo 0.44~0.65 | TS≥415MPa, YS≥205MPa, EL≥20%, H≤163HB |
WP22 | ASTM A234 | C 0.05~0.15, Cr 2.00~2.50, Mo 0.87~1.13 | TS≥415MPa, YS≥205MPa, EL≥20%, H≤163HB | |
Austenitic Stainless Steel | 304 | ASTM A403 | C≤0.08, Cr 18.0~20.0, Ni 8.00~10.5 | TS≥520MPa, YS≥205MPa, EL≥35%, H≤90HRB |
304L | ASTM A403 | C≤0.03, Cr 18.0~20.0, Ni 8.00~12.0 | TS≥480MPa, YS≥170MPa, EL≥35%, H≤90HRB | |
316 | ASTM A403 | C≤0.08, Cr 16.0~18.0, Ni 10.0~14.0, Mo 2.00~3.00 | TS≥520MPa, YS≥205MPa, EL≥35%, H≤90HRB | |
316L | ASTM A403 | C≤0.03, Cr 16.0~18.0, Ni 10.0~14.0, Mo 2.00~3.00 | TS≥480MPa, YS≥170MPa, EL≥35%, H≤90HRB | |
321 | ASTM A403 | C≤0.08, Cr 17.0~19.0, Ni 9.00~12.0, Ti≥5×C | TS≥520MPa, YS≥205MPa, EL≥35%, H≤90HRB |
Process:
Packing:
