Pressure Vessel
October 2021 - November 2021
Figure 1: Exploded view of pressure vessel.
Background and Key Design Features
In a team of 4 students, I designed, machined, and tested
a gas pressure vessel to be used in a laboratory environment.
The vessel was required to hold 50-60cc of fluid at
a pressure of 750psi and to cost no more than $100
in parts from McMaster Carr. An exploded view of the
final design is shown to the left in Figrue 1. The
vessel is made from 1215 steel and is 5.76” in length
and 3” in outside diameter. To prevent fluid leakage,
the team selected an O-ring face seal between the cap
and the body of the vessel with 4 hex head screws to
secure the two components together. A face seal was
chosen over a plug due to ease of machining. The cap
is complete with a 1/4 NPT pipe fitting through which
fluid can enter and exit the vessel.
Figure 2: Assembled view of pressure vessel.
The final cost
of the machined pressure vessel is $57.48, which is
well below budget. See Table 1 for a costed bill of
materials. The minimum factor of safety (FOS)
for the design was computed to be 2 due to the fact that the selected
O-ring is rated for a maximum fluid pressure of 1500psi.
After assembly, the pressure vessel was successfully tested up
to 1000psi. A view of the assembled pressure vessel is shown
in Figure 2.
Table 1: Costed Bill of Materials
| Part Name | Part Number | Quantity | Cost per unit |
|---|---|---|---|
| 1215 Carbon Steel - 3” diameter, 6” long | 4416T29 | 1 | $44.79 |
| Oil Resistant Buna-N O-Ring - ⅛” Fractional Width, 221 | 9452K42 | 1 | $0.13 |
| Zinc Yellow-Chromate Plated Hex Head Screw, Grade 8 Steel, 1/4"-20 Thread Size, 1" Long - Washers Included | 92620A542 | 4 | $0.14 |
| Swagelok B-400-1-4 Fitting | N/A | 1 | $3.70 |
| Total: | $57.48 | ||