NU-SAF Rupture Disks

Reliable overpressure relief is assured with components which cover a wide range of applications and service pressures

Features

1. Sizes 1″ to 8″ (25 mm – 200 mm).
2. Pressures 19 – 1450 psig (1.3 – 100 bar).
3. 80% operating ratio.
4. ± 5% Burst Tolerance.
5. Flat Seal.
6. Metal-to-Metal “bite type” seal.
7. Tension loaded.

Benefits

1. Minimal fragmentation.
2. Liquid and Gas service.
3. Extended life.
4. Reliable.
5. Easy Installation.
6. Leak-tight.
7. Fail-safe.
8. No vacuum support needed.

The Nu-SafT System introduces a new concept that combines the benefits of advanced technology with the simplicity of a basic style. Reliable overpressure relief is assured with components which cover a wide range of applications and service pressures.

Overpressure relief from 19 psig (1.3 bar) to 1450 psig (100 bar) is assured in a range of sizes from 1 inch (25 mm) to 8 inch (200 mm).

The Nu-SafT System consists of an inlet and an outlet of the NX-7R Safety Head plus the XN or LCN Rupture Disk, depending on the pressure required. Refer to Figure 1.

The XN Rupture Disk (Bursting Disc) incorporates precision scoring technology in a metal, tension loaded design. The precision scoring design minimizes the possibility of disk fragmentation. Operating pressure may be extended to 80% of the disk’s burst rating without the risk of metal fatigue and subsequent reduction in normal service life. The new design exhibits no premature failure or fatigue cracks after extended pressure cycle testing from vacuum to 80% of the disk’s burst rating. The XN Rupture Disk (Bursting Disc) design can withstand full vacuum without the need for a vacuum support.

For the lower pressure ranges the LCN Rupture disk is available. This is a composite disk comprised of three parts: (1) A slotted metal top section is the pressure controlling element. (2) A fluoropolymer seal isolates the top section from the process. (3) The slotted metal bottom section will withstand vacuum. The flat design minimizes the possibility of disk damage during installation.

The simplicity of the NX-7R Safety Head design incorporates several features which allow easy installation. The Quick-Sert Safety Head with its reduced diameter fits inside the studs of two companion flanges. Asymmetric alignment pins in the Safety Head mate with location holes in the rupture disk (bursting disc), thus eliminating incorrect installation and slippage. The flat set design in combination with a metal-to-metal “bite-type” seal provides a leak-tight system. The NX-7R Safety Head and rupture disk (bursting disc) are easily pre-assembled with side lugs.

XN Precision Scored Rupture Disk (Bursting Disc)

• Solid Metal
• Precision Scored
• Minimal fragmentation
• Can withstand vacuum without support
• Operates up to 80% of the disk’s rated pressure. (Consult factory for tighter operating ratio and manufacturing ranges.)
• Liquid and gas service (acceptable for liquid service with compressible gas pocket between liquid and disk.)
• Disks damaged or installed incorrectly will burst at rated pressure or lower.
• Can be used in pressure cycling conditions.

Specifications For Type XN Rupture Disk (Bursting Disc)

MIN/MAX PRESSURE RATING AT 72o F (22o C)(Minimum burst pressures for pressure cycling and vacuum service conditions, lower pressures are available for non-vacuum service conditions.)
DISK SIZE		MINIMUM PRESSURES												MAXIMUM PRESSURES ALL MATL.
		ALUM.		NICKEL 200		MONEL 400		INCONEL 600		HAST. C-276		316SS
in.	mm	psig	bar	psig	bar	psig	bar	psig	bar	psig	bar	psig	bar	psig	bar
1	25	60	4.2	70	4.8	115	7.9	115	7.9	180	12.4	125	8.6	1450	100
1.5	40	55	3.8	65	4.5	105	7.2	105	7.2	170	11.7	115	7.9	1450	100
2	50	55	3.8	60	4.2	90	6.2	90	6.2	160	11.0	100	6.9	1450	100
3	80	55	3.8	65	4.5	75	5.2	80	5.5	140	9.7	95	6.6	725	50
4	100	55	3.8	80	5.5	90	6.2	90	6.2	155	10.7	95	6.6	725	50
6	150	55	3.8	85	5.9	95	6.6	95	6.6	165	11.4	95	6.6	725	50
8	200	55	3.8	85	5.9	100	6.9	100	6.9	175	12.0	95	6.6	725	50

*Minimum burst pressuresa for pressure cycling and vacuum service conditions, lower pressures are available for non-vacuum service conditions.

Recommended maximum temperature for each metal is:

Metal	oF	oC
Aluminum	250	121
Nickel 200	750	399
Monel 400	800	427
Inconel 600	900	482
316 SS	900	482
Hastelloy C-276	900	482

Fluoropolymer liners are available in all sizes on either the process or downstream side. Fluoropolymer generally is used. Other appropriate fluorocarbon polymers may be supplied.

Manufacturing Range

A 5% manufacturing range is standard. Consult the factory for tighter operating ratio and manufacturing range.

The total range is placed on the minus side of the requested nominal rating.

Example:

If an XN Rupute Disk is ordered for a 725 psig (50 bar) burst pressure and a 5% manufacturing range, it may be tagged at a pressure between 689 psig (47.5 bar) and 725 psig (50 bar).

Tolerances:

Burst tolerances are the maximum variation from the above tagged burst pressure.

Example:
Disks tagged above 40 psig (2.75 bar) ± 5%
Disks tagged 40 psig (2.75 bar) and below ± 2 psig (1.38 bar).

**Consult factory for tighter operating ratio and manufacuring range

LCN Low Pressure Rupture Disk (Bursting Disc)

• Composite slotted metal type.
• Fluoropolymer liners provide seal and corrosion resistance.
• Can withstand full vacuum.
• Operates up to 80% of the disk’s rate pressure.
• Suitable for liquid and gas applications.
• Disks damaged or installed incorrectly will burst at rated pressure or lower.
• Standard materials of construction 316SS/Fluoropolymer/316SS. Consult BS&B Safety Systems for other materials.Specifications For Type LCN Rupture Disk (Bursting Disc)
  

  MIN/MAX PRESSURE RATING AT 72o F (22o C)(To determine Burst Pressure Ratings at elevated or cold temperatures, refer to the temperature conversion table following this section.)
  DISK SIZE		MATERIAL 316SS/TEF*/316SS (For other materials, consult BS&B Safety Systems.)
  		MINIMUM		MAXIMUM
  in.	mm	psig	bar	psig	bar
  1	25	50	3.45	125	8.62
  1.5	40	35	2.41	115	7.93
  2	50	19	1.3	100	6.89
  3	80	19	1.3	90	6.21
  4	100	19	1.3	80	5.52
  6	150	19	1.3	70	4.83
  8	200	19	1.3	65	4.48

  Fluoropolymer liners are available in all sizes on either the process or downstream side. Fluoropolymer generally is used. Other appropriate fluorocarbon polymers may be supplied.

  Recommended Temperature Limits

  	oF	oC
  Minimum	– 40	– 40
  Maximum	400	204

  Manufacturing Range

  A 10% manufacturing range is standard. The total range is placed on the minus side of the requested nominal rating.

  Example:

  If an LCN Rupture Disk (Bursting Disc) is ordered with a 29 psig (2 bar) burst pressure and a 10% manufacturing range, it may be tagged at a pressure between 26 psig (1.8 bar) and a 29 psig (2 bar).

  Burst Tolerance

  Burst Tolerances are the maximum variation from the above tagged burst pressure.

  Example:

  Disks tagged above 26 psig (1.8 bar) ± 5%.

  Disks tagged 26 psig (1.8 bar) and below ± 7%.

NX-7R Safety Head

• Quik-Sert reduced diameter fits between the studs of two companion flanges.
• Positive locating pins center the disk correctly in the NX-7R Safety Head, thus eliminating disk slippage and possible incorrect installation.
• Metal-to-Metal “bite-type” seal prevents leakage.
• The inlet and outlet of the NX-7R Safety Head are held together by side lugs.
• Standard material 316SS. Consult BS&B Safety Systems for other materials.

Specifcations for Type NX-7R Safety Head

Nominal Size		SAFETY HEAD FLANGE RATING (Consult BS&B Safety Systems for tongue/groove applications. 1/4″ NPT is available in outlet when used for Relief Valve Isolation.)				“A” OUTSIDE DIAMETER		“B” OVERALL HEIGHT
in.	mm	ANSI & BS 1560	BS 4504 & DIN	JIS	BS10	in.	mm	in.	mm
1	25	150	–	–	D-E	2 5/8	67	1 3/8	35
1	25	300/600	10/16/25/40	10/16/20/30/40	F	2 13/16	71	1 3/8	35
1.5	40	150	–	–	D-F	3 3/8	86	1 3/8	35
1.5	40	300/600	10/16/25/40	10/16/20/30	–	3 5/8	92	1 3/8	35
1.5	40	–	–	40	–	3 13/16	97	1 3/8	35
2	50	–	–	–	D-E	3 3/4	96	1 3/8	35
2	50	150	–	10/16/20/30/40	–	4	102	1 3/8	35
2	50	300/600	10/16/25/40	–	F	4 1/4	108	1 3/8	35
3	80	–	–	–	D-E	5	128	1 3/8	35
3	80	150	–	10	–	5 1/4	134	1 3/8	35
3	80	–	–	16/20/30/40	–	5 1/2	140	1 3/8	35
3	80	300	10/16/25/40	–	F	5 11/16	144	1 3/8	35
4	100	–	–	10	–	6 1/4	159	1 3/8	35
4	100	–	10/16	16/20	D-E	6 3/8	162	1 3/8	35
4	100	150	25/40	30	F	6 11/16	170	1 3/8	35
4	100	300	–	–	–	7	178	1 3/8	35
4	100	–	–	40	–	7 1/4	183	1 3/8	35
6	150	150	10/16	10	D-E	8 1/2	218	1 3/8	35
6	150	–	–	16	–	9 1/4	235	1 3/8	35
6	150	300	–	–	–	9 3/4	248	1 3/8	35
6	150	–	25/40	–	–	8 13/16	224	1 3/8	35
6	150	–	–	–	F	9 3/8	238	1 3/8	35
8	200	–	–	10	–	10 5/8	270	1 5/8	41
8	200	150	10/16	–	D-E	10 3/4	274	1 5/8	41
8	200	–	–	16	–	11	280	1 5/8	41
8	200	–	25	–	–	11 7/8	284	1 5/8	41
8	200	–	40	–	–	11 3/8	290	1 5/8	41
8	200	–	–	–	F	11 7/8	302	1 5/8	41
8	200	300	–	–	–	12	305	1 5/8	41

Ordering Information:

For all your rupture disk (bursting disc) needs, rely on BS&B. Contact the representative in your area or contact BS&B Safety Systems today.