ASTM A234 WPB Cap is a type of pipe fitting used to seal the end of a pipe. The prefabricated pipe used A234 WP8 DN1800 FBE+3LPE CAP. The ASTM A234 Grade WPB Butt Weld Pipe Fitting is made from carbon steel and is designed to withstand high pressures and temperatures. The WPB in its name refers to its composition, which is W for weldable, P for pressure and B for black.
ASTM A234 WPB End Cap is commonly used in piping systems for various industries including petrochemical, oil and gas, chemical and power generation. Carbon Steel ASME SA234 WPB Seamless End Cap is also used in plumbing and HVAC (heating, ventilation and air conditioning) systems.
The design of the A234 carbon steel forged fitting is simple yet effective. It is installed by welding onto the end of the pipe. The ASTM A234 WPB end cap acts as a barrier, preventing liquids or gases from entering or leaving the pipe. This is essential to maintain the integrity of the piping system.

ASTM A234 WPB Pipe Cap Chemical Composition
| Grade | C | Mn | P | S | Si | Cr | Mo | Ni | Cu | V | Nb |
| WPB | 0.3 | 0.29-1.06 | 0.05 | 0.058 | 0.1min | 0.4 | 0.15 | 0.4 | 0.4 | 0.08 | 0.02 |
| WPC | 0.35 | 0.29-1.06 | 0.05 | 0.058 | 0.1min | 0.4 | 0.15 | 0.4 | 0.4 | 0.08 | 0.02 |
| WP11 CL1 | 0.05-0.15 | 0.30-0.60 | 0.03 | 0.03 | 0.50-1.00 | 1.00-1.50 | 0.44-0.65 | – | – | – | – |
| WP11 CL2/3 | 0.05-0.20 | 0.30-0.80 | 0.04 | 0.04 | 0.50-1.00 | 1.00-1.50 | 0.44-0.65 | – | – | – | – |
Notes:
For each reduction of 0.01% below the specified C maximum, an increase of 0.06% Mn above the specified maximum will be permitted, up to a maximum of 1.35%.
The sum of Cu, Ni, Cr, and Mo shall not exceed 1.00%.
The sum of Cr and Mo shall not exceed 0.32%.
The maximum carbon equivalent (C.E.) shall be 0.50, based on heat analysis and the formula C.E.=C+Mn/6+(Cr+Mo+V)/5+(Ni+Cu)/15.
ASTM A234 WPB Cap Equivalent
| Pipe | Pipe Cap Fitting | Flanges | Valves | Bolts & Nuts |
| A106 Gr A | A234 Gr WPA | A105 | A216 Gr WCB | A193 Gr B7 A194 Gr 2H |
| A106 Gr B | A234 Gr WPB | A105 | A216 Gr WCB | |
| A106 Gr C | A234 Gr WPC | A105 | A216 Gr WCB |
ASTM A234 WPB Cap Mechanical Properties
Check below ASTM A234 WPB Pipe Cap Properties before you order.
| Tensile Requirements | WPB | WPC, WP11CL2 | WP11CL1 | WP11CL3 |
| Tensile Strength, min, ksi[MPa] | 60-85 | 70-95 | 60-85 | 75-100 |
| (0.2% offset or 0.5% extension-under-load) | [415-585] | [485-655] | [415-585] | [520-690] |
| Yield Strength, min, ksi[MPa] | 32 | 40 | 30 | 45 |
| [240] | [275] | [205] | [310] |
Where the wall thickness lies between two values above, the min elongation value is determined by the following equations:
Longitudinal E=48t+15.00
Transverse E=32t+10.00
E = elongation in 2in [50mm], %
t = actual thickness of specimen, in [mm]
Cap A234 WPB Dimensions
| Nominal Pipe Size | Outside Diameter | Inside Diameter | Wall Thickness | Length | Pipe Schedule | Weight Pounds |
| 1/2 | 0.84 | 0.622 | 0.109 | 1 | 40 | 0.08 |
| 3/4 | 1.05 | 0.824 | 0.113 | 1.25 | 40 | 0.14 |
| 1 | 1.32 | 1.049 | 0.133 | 1.5 | 40 | 0.21 |
| 1 1/4 | 1.66 | 1.38 | 0.14 | 1.5 | 40 | 0.33 |
| 1 1/2 | 1.9 | 1.61 | 0.145 | 1.5 | 40 | 0.54 |
| 2 | 2.38 | 2.067 | 0.154 | 1.5 | 40 | 0.8 |
| 2 1/2 | 2.88 | 2.469 | 0.203 | 1.5 | 40 | 1 |
| 3 | 3.5 | 3.068 | 0.216 | 2 | 40 | 1.7 |
| 3 1/2 | 4 | 3.548 | 0.226 | 2.5 | 40 | 2.3 |
| 4 | 4.5 | 4.026 | 0.237 | 2.5 | 40 | 2.8 |
| 5 | 5.56 | 5.047 | 0.258 | 3 | 40 | 4.6 |
| 6 | 6.62 | 6.065 | 0.28 | 3.5 | 40 | 6.9 |
| 8 | 8.62 | 7.981 | 0.322 | 4 | 40 | 11.8 |
| 10 | 10.75 | 10.02 | 0.365 | 5 | 40 | 20.8 |
| 12 | 12.75 | 12 | 0.375 | 6 | * | 30.3 |
| 14 | 14 | 13.25 | 0.375 | 6.5 | 30 | 36.5 |
| 16 | 16 | 15.25 | 0.375 | 7 | 30 | 43.5 |
| 18 | 18 | 17.25 | 0.375 | 8 | * | 57 |
| 20 | 20 | 19.25 | 0.375 | 9 | 20 | 75.7 |
| 24 | 24 | 23.25 | 0.375 | 10.5 | 20 | 101 |
| 30 | 30 | 29.24 | 0.38 | 10.5 | * | 137 |
| 36 | 36 | 35.24 | 0.38 | 10.5 | * | 175 |
| 42 | 42 | 41.24 | 0.38 | 12 | * | 229 |
| 48 | 48 | 47.24 | 0.38 | 13.5 | * | 350 |
C&N Hongcheng, Carbon Steel ASTM A234 Grade WPB Butt Weld Pipe Fittings, Carbon Steel ASME SA234 WPB Seamless End Caps Stockist, Carbon Steel A234 Forged Fittings, ASTM A234 WPB End Cap. China manufacture. Contact us for a quote now!
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