BSM & RJT Union Blank Cap
A removable blank cap for closing a BSM or RJT union connection in process pipework. Choose the union profile first, then compare the separately listed BSM and RJT dimensions and material options.
BSM material options | SS304, SS316L |
|---|---|
BSM series size range | 25~152mm |
Union series | BSM / RJT |
Component type | Union blank cap / blanking disc |
Profile | Shallow dished centre; annular rim |
Size
Product overview
A removable closure for a union connection
A union blank cap closes an unused connection while retaining access for later inspection or changes to the pipework. Also called a union blank or blanking disc, it is held in the matching union assembly by the union nut and seal. The dished centre and annular rim distinguish this component from a threaded plug or a Tri-Clamp blind cap.
Choose BSM or RJT before choosing size
BSM and RJT are separate union interfaces. Start with the series of the existing union, then compare the cap profile, outside diameter and sealing-seat dimensions with the relevant drawing. A nominal pipe size alone does not establish a fit. The BSM and RJT dimension tables are separate references, so values from one table should not be combined with the other.
Material options and process use
The BSM series lists SS304 and SS316L options over a 25–152 mm range. The separate BSM and RJT dimensional examples shown here are grade 304. These union closures are used in dairy, food, beer and beverage pipework; material and seal selection depend on the process liquid, cleaning chemicals and operating conditions.
Replacement and ordering
For a replacement, identify the union series and size, then check the existing nut, mating seat and seal. Inspect contact surfaces for damage before reassembly. For an enquiry, provide the required material, quantity and the applicable drawing or measured dimensions; this helps distinguish similar-looking BSM and RJT blanks.
Technical specifications
Product specifications
- BSM surface finish
- Ra<0.8umJ&O BSM series only
- RJT reference grade
- 304Only the listed RJT dimensional configurations
BSM blank · grade 304 dimensions (1–4 in)
Only 302 grade 304, 1–4 inch configurations; not 316L or the full 25–152mm series.
Units: mm (unless stated otherwise)
| Item | 1" 25.4 | 1 1/2" 38.1 | 2" 50.8 | 2 1/2" 63.5 | 3" 76.2 | 4" 101.6 |
|---|---|---|---|---|---|---|
| A | 42 | 55 | 67 | 80 | 93 | 118 |
| B | 4 | 4 | 4 | 4 | 4 | 4 |
| C | 8.5 | 8.5 | 8.5 | 8.5 | 8.5 | 8.5 |
| D | 31 | 44 | 56 | 69 | 82 | 107 |
RJT Union Blank
Only the listed RJT union blank configurations.
Units: Units: see column headings.
| Inch size | Metric size | Grade | a | b |
|---|---|---|---|---|
| 1/2" | 12.7 | 304 | 17 | 7.5 |
| 3/4" | 19.05 | 304 | 24 | 7.5 |
| 1" | 25.4 | 304 | 42 | 8.5 |
| 1 1/4" | 31.8 | 304 | 48 | 8.5 |
| 1 1/2" | 38.1 | 304 | 55 | 8.5 |
| 2" | 50.8 | 304 | 67 | 8.5 |
| 2 1/2" | 63.5 | 304 | 80 | 8.5 |
| 3" | 76.2 | 304 | 93 | 8.5 |
| 4" | 101.6 | 304 | 118 | 8.5 |
| 5" | 127 | 304 | 144 | 8.5 |
| 6" | 152.4 | 304 | 168 | 8.5 |
Need a different size, connection or document?
Discuss your requirementsFrequently asked questions
Are BSM and RJT blank caps interchangeable?
Do not assume interchangeability. Confirm the specific union profile, sealing face and dimensions with the applicable drawing before selection.
Are both stainless grades available in every listed size?
The source series lists SS304 and SS316L as options; the separate BSM and RJT reference tables identify grade 304. Confirm the grade and size for the required configuration.
