Small-Scale Force Testing
For prototype iterative development
Bostec’s Force Testing UHV Laboratory is for testing customer designed metal seal flange and base assemblies, along with their prototype metals seals. The goal is generally to reduce the footprint of the UHV seal to the smallest possible level. The objective is to attain the smallest footprint, lowest force and easiest to compress combination that is still robust enough for regular production use.
For gland and seal designs that fit within normal and known parameters, this sort of iterative development is not needed. However, when the gland and seal designs are hybrids, or where compression and crush values have no known comparative values, iterative development with actual force testing is useful.
Our customers often use FEA to approximate seal designs, which is helpful in suggesting general parameters. However, our experience is that all too often, FEAs are too inaccurate to be relied upon for final designs. Actual force testing produces hard empirical data that can be relied upon.
There are 6 basics steps in most UHV seal development projects, shown here.
As as starting point, Bostec maintains the largest library of force values for all common types of metal seals allowing us to custom tailor designs for each application taking into account desired UHV levels, thermal cycling, corrosives, available installation footprint, types of fasteners or compression mechanisms, dynamic and seismic loads, radiation considerations and more.
Force-test flanges and gaskets for each junction
- Determine force to first UHV seal
- Determine force to full crush
- Impose structural loads, thermal loads, bake cycles, etc -
- Determine appropriate fasteners / closure devices based on actual force values
Study ease of installation, spacing conflicts, thermal cycling, bake, seismic, repeated thermal cycles, shock tests, clown mallet.
Force Testing – Bostec Testing Lab
Force capacity: 80,000# – 1,000,000#
DN100 / CF6.00 / OFS COPPER – TEST 5A
Bostec Customers
BOSTEC’S ROLE: FACILITY-WIDE RESIGN
Europa Clipper is a planned Jupiter orbiter with a focus to conduct detailed reconnaissance of Jupiter’s moon Europa and investigate whether the icy moon could harbor conditions suitable for life. The mission will place a spacecraft in orbit around Jupiter in order to perform a detailed investigation of Europa — a world that shows strong evidence for an ocean of liquid water beneath its icy crust and which could host conditions favorable for life.
The mission will send a highly capable, radiation-tolerant spacecraft into a long, looping orbit around Jupiter to perform repeated close flybys of the icy moon.
NASA has selected nine science instruments for the mission. The selected payload includes cameras and spectrometers to produce high-resolution images of Europa’s surface and determine its composition. An ice penetrating radar will determine the thickness of the moon’s icy shell and search for subsurface lakes similar to those beneath Antarctica’s ice sheet. The mission will also carry a magnetometer to measure the strength and direction of the moon’s magnetic field, which will allow scientists to determine the depth and salinity of its ocean. Gravity measurements will also help confirm the existence of Europa’s subsurface ocean.
Among the nine instruments carried, the Europa Clipper rover will have a MAss SPectrometer for Planetary EXploration/Europa (MASPEX) developed by the Southwest Research Institute (SwRI), San Antonio. This instrument will determine the composition of the surface and subsurface ocean by measuring Europa’s extremely tenuous atmosphere and any surface material ejected into space.
Bostec Engineering’s H-Seals are used as the design basis for MASPEX components and Bostec manufactured the metal seals and component covers, which have all been sputtered with 50 microinches of pure gold for corrosion protection.
