Sigma™ and Sigma EXL™

Sizes & Pressures

Sigma™ and Sigma EXL™ Disk Specifications Minimum/Maximum Pressure with Rating at 72° (22°C)

in	mm	psig		barg		psig		barg		psig		barg		psig		barg		psig		barg
Disk Size		Nickel Alloy 200				Monel^® Alloy 400				Inconel^® Alloy 600				Hastelloy^® Alloy C-276				316SS
in	mm	min	max	min	max	min	max	min	max	min	max	min	max	min	max	min	max	min	max	min	max
1	25	35	500	2.41	34.47	58	500	4.00	34.47	50	500	3.45	34.47	55	500	3.79	34.47	35	500	2.41	34.47
1.5	40	30	400	2.06	27.58	45	400	3.10	27.58	45	400	3.10	27.58	45	400	3.10	27.58	30	400	2.07	27.58
2	50	25	400	1.72	27.58	30	400	2.07	27.58	30	400	2.07	27.58	30	400	2.07	27.58	25	400	1.72	27.58
3	80	20	400	1.38	27.58	22	400	1.52	27.58	22	400	1.52	27.58	25	400	1.72	27.58	20	400	1.38	27.58
4	100	16	400	1.10	27.58	18	400	1.24	27.58	18	400	1.24	27.58	20	400	1.38	27.58	16	400	1.10	27.58
6	150	15	225	1.03	15.51	15	225	1.03	15.51	15	225	1.03	15.51	20	225	1.38	15.51	15	225	1.03	15.51
8	200	15	125	1.03	8.62	15	125	1.03	8.62	15	125	1.03	8.62	20	125	1.38	8.62	15	125	1.03	8.62
10	250	15	100	1.03	6.89	15	100	1.03	6.89	15	100	1.03	6.89	20	100	1.38	6.89	10	100	0.69	6.89
12	300	15	75	1.03	5.17	15	75	1.03	5.17	15	75	1.03	5.17	20	75	1.38	5.17	10	75	0.69	5.17

NOTE: Hastelloy^® is a trademark of Haynes International Inc. Monel^® and Inconel^® are registered trademarks of Special Metals Corporation and its subsidiaries.

Burst Tolerance

Marked Burst Pressure	Burst Tolerance
≤ 40 psig (2.76 barg)	± 2 psig (0.138 barg)
> 40 psig (2.76 barg)	± 5%

Safety Heads & Sensors

Safety Heads

SRI-7RS
Safety Head

SRB-7RS
Safety Head

SRB-7FS
Safety Head

S90-7R
Safety Head

Sensors

Burst Alert Sensors (BAS+)
Round or Square

Leak Detector Alert Sensors (LDAS+) Round or Square

Accessories

BS&B supplies many of the accessories required to safely and conveniently install our overpressure relief devices and complementary products. Through our professional team and global network of sales engineers and procurement personnel, we are able to provide the highest quality accessory products to meet your installation requirements.

Saf-T-Change Quick Disk Replacement (QDR)

After activation, the replacement disk is quickly slid into place. Saving hours of lost production due to blown rupture disks.

Tell-Tale Assemblies & Excess Flow Valves/Gauges

A gauge tap in the outlet flange of the safety head may be considered when the safety head is installed in a vertical position.

Spare Safety Heads & Cap Screws

Jackscrews

When activated, the jackscrews effectively separate the flanges, providing adequate clearance to remove or insert a safety head and external gaskets.

Lifting Lug Eye Bolts

Eye bolts are recommended when weight and/or accessibility is a factor in lifting safety heads.

Baffle Plate

When a safety head is free-vented to atmosphere, a baffle plate may be considered to disperse overpressure and absorb recoil.

Documentation

Product Literature

Sta-Saf System

S90™, JRS™, FRS™, RLS™ and SKR™ reverse buckling disks. SRB-7RS™, S90-7R™ and SRB-7FS™ Safety Heads.

Sigma™ and Sigma EXL™

Rupture Disks (Bursting Discs) for the Highest Operating Pressure in Gas or Liquid Service.

Saf-T-Change™ QDR Rupture Disk Replacement System

Quick replacement of actives disk fast and with minimum process line exposure to personnel and the environment.

Burst Alert Sensors

A range of sensors suitable for different rupture disk types used to provide immediate warning of a ruptured disk., #77-1003

Detec Saf Alarm System – Burst Disk Monitor

Detec-Saf™ alarm system provides immediate warning and specific location of disk rupture and centralized monitoring of all disk locations.

Installations

Sigma EXL™, Sigma™, SKR™, and LPS™ Installation Instructions

Types Sigma EXL™, Sigma™, SKR™, and LPS™ Rupture Disks SRB-7RS™ and S90-7R™ Safety Heads

Burst Alert Sensor Installation Instruction

Burst Alert Leak Dectector Installation Instruction

Sizes & Pressures

Sigma™ and Sigma EXL™ Disk Specifications Minimum/Maximum Pressure with Rating at 72° (22°C)

in	mm	psig		barg		psig		barg		psig		barg		psig		barg		psig		barg
Disk Size		Nickel Alloy 200				Monel^® Alloy 400				Inconel^® Alloy 600				Hastelloy^® Alloy C-276				316SS
in	mm	min	max	min	max	min	max	min	max	min	max	min	max	min	max	min	max	min	max	min	max
1	25	35	500	2.41	34.47	58	500	4.00	34.47	50	500	3.45	34.47	55	500	3.79	34.47	35	500	2.41	34.47
1.5	40	30	400	2.06	27.58	45	400	3.10	27.58	45	400	3.10	27.58	45	400	3.10	27.58	30	400	2.07	27.58
2	50	25	400	1.72	27.58	30	400	2.07	27.58	30	400	2.07	27.58	30	400	2.07	27.58	25	400	1.72	27.58
3	80	20	400	1.38	27.58	22	400	1.52	27.58	22	400	1.52	27.58	25	400	1.72	27.58	20	400	1.38	27.58
4	100	16	400	1.10	27.58	18	400	1.24	27.58	18	400	1.24	27.58	20	400	1.38	27.58	16	400	1.10	27.58
6	150	15	225	1.03	15.51	15	225	1.03	15.51	15	225	1.03	15.51	20	225	1.38	15.51	15	225	1.03	15.51
8	200	15	125	1.03	8.62	15	125	1.03	8.62	15	125	1.03	8.62	20	125	1.38	8.62	15	125	1.03	8.62
10	250	15	100	1.03	6.89	15	100	1.03	6.89	15	100	1.03	6.89	20	100	1.38	6.89	10	100	0.69	6.89
12	300	15	75	1.03	5.17	15	75	1.03	5.17	15	75	1.03	5.17	20	75	1.38	5.17	10	75	0.69	5.17

NOTE: Hastelloy^® is a trademark of Haynes International Inc. Monel^® and Inconel^® are registered trademarks of Special Metals Corporation and its subsidiaries.

Burst Tolerance

Marked Burst Pressure	Burst Tolerance
≤ 40 psig (2.76 barg)	± 2 psig (0.138 barg)
> 40 psig (2.76 barg)	± 5%

Safety Heads & Sensors