Rupture disk manufacturers burst at least two disks per lot before shipping them to a customer.
As a consequence even if you want just one rupture disk you will be buying three. Therefore, the first usable rupture disk is comparatively expensive. Also for new installations, each installed rupture disk must be purchased along with a holder. However, the same holder may be used for replacement purchases as long as you buy the exact same rupture disk from the same manufacturer.
Below is a capital cost comparison between Continental Disc Corp. (www.contdisc.com) 3″ Ultrx Hastelloy C rupture disks with holders and Farris Engineering (www.cwfc.com) 2600 series relief valves, based on a budget estimate in year 2001 dollars.
| Basis: Continental Disc | Basis: Farris Engineering |
| 3″ Ultrx Hast C Disc = $2,600 for 1st usable disk, then $870 each | 3″ x 4″ Hast C 26KA10-120 = $13,400 |
| 3″ Ultrx Hast C Holder = $3,300 ea. | Â |
| TOTAL for one pair = $5,900 | Â |
| TOTAL for three pair = $14,240 | TOTAL for three = $40,200 |
This capital cost comparison will vary considerably with size and material of construction but you get the point. However please note that everything has a value and the loss of contents should be considered in the overall cost difference between a rupture disk and a relief valve
