Isolating a relief or safety valve from the process media through the installation of a rupture disc upstream of the valve inlet will eliminate exposure of the costly valve to effects of the media.

1. EARTH-FRIENDLY. COST-EFFECTIVE. SMART.
PRESSURE RELIEF VALVES
RUPTURE DISCS+
CTi Controltech
San Ramon, CA USA
925-208-4250
www.cti-ct.com

2. Pressure relief valves combined with rupture discs
Often thought of as substitute products, rupture discs and pressure relief valves (PRVs) are
used together to ensure protection and long-term savings. The combined use of rupture discs
and pressure relief valves has become common practice, especially in refineries, chemical and
petrochemical plants.
Advantages:
When in use, rupture discs provide a superior process seal reducing fugitive emissions
Valves reclose after an overpressure event, saving process media and allowing operation
to continue until the rupture disc can be replaced
Allows for less expensive valve material
Extends the valve’s life and requires less maintenance
Reduces overall cost and lead time
Isolation from Leakage
Pressure relief valves can be significant sources of media leakage and emissions. Due
to continually tightening government emission standards, small leaks can be more than
troublesome…theycanbeexpensive.ByisolatingtheinletofaPRV,apositivesealisestablished
to minimize leakage and reduce fugitive emissions that can escape up through the valve seat.
PRESSURE RELIEF VALVE RUPTURE DISC PRESSURE RELIEF VALVE
+ RUPTURE DISC
Leak Tight
No - leaks, which may result in
product loss
Yes Yes
Cost High Low Medium
Maintenance
High - must be shut down to be
checked periodically
Low Medium
Adjustable Yes No - fixed setting Yes
Reclosable Yes No Yes
Reusable Yes No - must be replaced after each use Valve is reusable, disc is not
PRESSURE RELIEF VALVE ADVANTAGE
RUPTURE DISCS+
A COMPARISON OF OPTIONS
P E R F O R M A N C E U N D E R P R E S S U R E
®

3. Isolation from Corrosion
Depending upon the corrosive nature of an application’s process media, maintaining
equipment for long-term service can be expensive due to the costs of exotic materials for valve
components or frequent changeouts caused by equipment deterioration. Isolating a valve with
a rupture disc minimizes corrosive effects by preventing continual contact between the valve’s
wetted parts and the system media.
Continental Disc Corporation Rupture Discs
The following are some of the Continental Disc Corporation rupture discs that could be used in
conjunction with a pressure relief valve:
HPX®
Rupture Discs
LOTRX®
Rupture Discs
MICRO X®
Rupture Discs
RCS Rupture Discs
Technical Considerations:
Severalcodesandstandardsrequiretheuseofatell-taledevicetoindicateorventpressure
betweentherupturediscandPRVensuringproperfunctionofthecombineddevices.Agauge
tap can be requested in the outlet of the rupture disc holder to allow for connection of a
tell-tale device.
The size of the rupture disc device is generally the same as the PRV inlet connection.
TheflowcapacityoftherupturediscincombinationwiththePRVisgenerallydeterminedby
correctingthevalvecapacitytoaccountfortherupturediscdevice.Forcertifiedrupturedisc/
pressure relief valve combination capacity factors, see our ASME Combination Capacity
Factors literature.
For rupture disc certified flow resistance values (KR
) to be used in evaluating flowing fluid
pressure drop from the vessel to the valve inlet (normally specified not to exceed 3% of the
valve set pressure), see our CERTIFLOW®
literature.
1” – 8” HPX®
and LOTRX®
reverse acting rupture discs assembled in HPX®
and LOTRX®
holders are designed to enable installation of the safety relief valve directly coupled with
the rupture disc holder. This is because the height of the holder outlet keeps the disc
petal out of the throat of the valve without the need of a spool piece, which helps to provide
very efficient flow characteristics for the assembly. See the HPX®
Rupture Disc Product
Family and Reverse Acting literature for more details.
NOTE: The HPX Rupture Disc holder does require a spool piece between the holder outlet and the inlet of a pressure relief
valve for 10” and 12” (250 mm and 300mm) sizes. For more details, see HPX Installation Instructions on contdisc.com.
Pressure
Relief Valve
Retrieval
Rope
ENVIRO-GUARD®
3-D Tag
Universal B.D.I.
®
(Burst Disc Indicator)
Tell-Tale
Assembly
Rupture Disc Device
Alarm System
P E R F O R M A N C E U N D E R P R E S S U R E
®
SANITRX HPX®
Rupture Discs for sanitary applications
CDC Rupture Discs with non-metallic seals
CDCV Rupture Discs with non-metallic seals

4. P E R F O R M A N C E U N D E R P R E S S U R E ®
Continental Disc Corporation reserves the right to alter the information in this publication without notice. // © 2014 Continental Disc Corporation
Reproduction without written permission is prohibited.
PRINTED IN U.S.A.
LIT1338 // 0114
HEADQUARTERS //
3160 W. Heartland Drive
Liberty, MO 64068 USA
Ph (816) 792 1500 | Fax (816) 792 2277
sales@contdisc.com
contdisc.com
THE NETHERLANDS
Energieweg 20
2382 NJ Zoeterwoude-Rijndijk
The Netherlands
Ph +(31) 71 5412221 | Fax +(31) 71 5414361
cdcnl@contdisc.com
CHINA
Room 1312, Tower B, COFCO Plaza
No. 8 JianGuoMenNei Avenue
Beijing (10005), P.R. China
Ph +(86) 10 6522 4885 | Fax +(86) 10 6522 2885
cdcchina@contdisc.com
INDIA
423/P/11, Mahagujarat Industrial Estate, Moraiya,
Sarkhej-Bavla Road, Ahmedabad (GJ)
382213 INDIA
Ph +(91) 2717 619 333 | Fax +(91) 2717 619 345
gcmpl@contdisc.com