Spiral Wound Gasket with Outer Centering Ring

Spiral Wound Gasket with Outer Centering Rings - Style SN 500 - CG

Spiral Wound Gasket with Outer Centering Ring is the one of popular type of spiral wound gasket, this type of gasket construction is that one winding ring with an outer centering ring. Spiral wound gasket with outer centering ring works by using an outside ring which accurately centers gasket on flange face, offers further radial strength to prevent gasket blow-out and works as a compression stop. It is suitable for use with flat face and raised face flanges up to and inclusive of class 2500.

The gasket can be offered according to EN1514-2 for use with DIN flange systems, EN12560-2 for use with flange systems according to EN1759-1 or ASME B16.5, ASME B16.20 for use with flange systems ASME B16.5, ASME B16.47 series A for use with flange systems according to ASME B16.47 series A and ASME B16.47 series B for use with flange systems according to ASME B16.47 series B.

What Makes the Spiral Wound Gasket So Popular?

This kind of gasket is super suitable for using the condition of high temperature, high pressure, and corrosive applications. It also allow a wide variety of available gasket materials combined for different industries, can satisfy anyone's need. And the v-shaped metal strip which called the winding, mixed with a filler like Graphite or PTFE to gain excellent sealing effect and quality, makes the gasket be a perfect seal.

The Most 4 Common Types of Spiral Wound Gasket

CG Style (Spiral Wound Gasket with Outer Centering Ring)

It is one of the most widely used and also widely available configuration of spiral wound gaskets. CG Style gaskets have a reliable metal ring over the outer diameter known as the centering guide (CG). This guide makes it possible for the installer to more accurately center the gasket on the flange face while supplying durability on the outer ring. CG style gaskets are widely-used with both flat and raised-face flanges in a wide variety of program.

CGI Style (Spiral Wound Gasket with Inner and Outer Centering Ring)
Just like the CG Style referred to above, CGI gaskets come with an outer ring, in addition they provide an inner ring safeguarding the inner diameter of the gasket against heat, corrosion as well as blow-outs making it ideal in vacuum programs. CGI Style gaskets may be used with both flat and raised-face flanges.

R Style (Spiral Wound Gasket without inner or outer ring)

The most basic setup of spiral wound gaskets, the R-Style includes only stainless steel winding and the filler elements. The inner and outside diameter are generally strengthened by several layers of the winding material minus the filler. The inner part of the R-style gasket is comprised of winding and filler material. This fashion is commonly used with tongue and groove, flat-faced to grooved, and male to female flange connectors. They are also regularly employed in valve bonnets and pump casings.

RIR Style (Spiral Wound Gasket with Inner Ring) 

It Is similar to the R-Style gasket in its simple construction but comes with an inner liner ring that acts as a support. The inner ring makes a pressure stop and fills the void between the inner diameter of the gasket and the flange bore. This minimizes the deposition of solids and reduces turbulence of fluids. RIR Design gaskets are widely-used on male along with female flange connectors.

Spiral Wound Gasket Selected Material

Metal Winding Ring	Gasket Inner Ring Materials	Outer Centering Ring	Graphite Winding Filler
V Shape or W-shape stainless steel Stainless Steel 316L Stainless Steel 304 Stainless Steel 310 Stainless Steel 316Ti Stainless Steel 347 Monel 400 Nickel 200 Inconel 600 Inconel 625 Inconel X750 Incoloy 800 Incoloy 825 Hastalloy B2	Stainless steel 316L Stainless Steel 304 Stainless Steel 310 Stainless Steel 316Ti Stainless Steel 347 Monel 400 Nickel 200 Inconel 600 Inconel 625 Inconel X750 Incoloy 800 Incoloy 825 Hastalloy B2	Carbon Steel Stainless steel 304 Stainless Steel 316L Stainless Steel 321 Stainless Steel 347 Stainless Steel 410 Monel 400 Nickel 200 Inconel 600 Incoloy 800 Incoloy 825 Hastalloy B2 Hastalloy C276 Titanium Alloy 20	Flexible Graphite Non-asbestos  Mica Tape Ceramic PTFE

Spiral Wound Gasket Torque Value Chart

To Set Up and make use of the spiral wound gasket effectively, we need to be aware of torque beliefs since it is vital. Torque principles restrict bare minimum and optimum gasket sitting stresses based upon various pressure school in accordance with ASME B16.20 common and a number of working situations. (greatest stress ratings for provided stress type, not hydro analyze strain). Extreme running situations for example substantial temperatures may decrease bolt deliver durability. Care should be employed in these programs. The below torque beliefs are for basic use only. For essential or intense apps (substantial temperatures and stress), consult with us for more information.

Flange Size (inch)	Suggested Torque Value (Ft-Lbs) for CGI Spiral wound gasket with inner and outer ring
	Class 150	Class 300	Class 400	Class 600	Class 900	Class 1500	Class 2500
1/2	30-50	30-40	30-40	30-40	70-120	70-120	50-100
3/4	30-50	60-80	60-70	60-80	70-120	70-120	50-100
1	30-60	60-80	60-80	60-80	170-290	110-190	110-160
1 1/2	30-60	100-140	100-140	100-140	110-190	290-310	310-360
2	60-120	60-80	60-80	60-80	110-190	130-190	220-250
2 1/2	60-120	100-140	100-150	100-140	170-290	190-290	300-360
3	90-120	100-150	100-120	100-150	140-230	265-360	460-500
3 1/2	60-120	100-170	160-290	170-290
4	70-120	100-200	160-320	190-320	255-420	415-520	710-800
5	100-200	110-200	210-320	280-490	360-600	585-800	1280-1500
6	130-200	110-200	190-320	260-460	300-500	530-680	1870-2200
8	180-200	180-320	310-490	400-700	485-800	850-1100	1780-2200
10	170-320	250-460	360-710	500-800	505-800	1570-2000	3000-4400
12	240-320	360-700	510-1000	500-850	570-850	1500-2200	4610-5920
14	300-490	360-610	500-870	680-950	630-940	1500-2200
16	310-490	500-920	680-1250	800-1210	910-1290	2120-3180
18	490-710	500-1000	680-1340	1100-1790	1570-2340	2940-4400
20	430-710	500-1000	800-1430	1100-1640	1740-2570	5150-7720
24	620-1000	800-1600	1500-2270	2000-2670	2945-5140	8340-12500

Spiral Wound Gasket Manufacturing Process

From the time 1912, the asbestos spiral wound gasket was invented and used. Till now different stainless steel materials, and sealing element fillers such as ptfe, graphite, mica and other non-asbestos materials, safer and better sealing effect. And different types of spiral wound gasket invented, but the 3 key structures for spiral wound gasket will be always: Inner Ring, Outer Centering Guide Ring and Sealing Element also called Winding Ring.

Below is the process and methods to prouce Inner Ring, Outer Centering Guide Ring and Sealing Element.

1 - Inner and Outer Ring

The inner and outer ring can be manufactured by below 2 methods.

A. For the inner ring and outer centering ring of spiral wound gasket, the first method is cutting out the metal ring from stainless steel sheet by using a punch press, water jet or laser cutting machine when the ring gasket below 150 to 200 mm diameter. After the ring comes out, then put onto a lathe where a convex profile can be machined onto the outer diameter edge for inner rings, also a concave profile is machined onto to inner diameter edge for outer rings. 

B. The second method is that use Spiral Wound Gasket Ring Bending machine to bend the stainless steel tape into the correct radius of the spiral wound gasket inner or outer ring, then cut the excess length of the tape by a bandsaw to get a right circle size of the ring. And then form the tape into a complete gasket ring by spiral wound gasket automatic welding machine, and sand down the gasket ring to be a smooth ring. After this use a spiral wound gasket angling machine to machine the inner ring for a convex profile, a spiral wound gasket grooved machine machine the outer ring for a concave profile. This method need more lot of time and need the workers quite skilled, but after use our advanced spiral wound gasket machine, you will easily produce the spiral wound gasket inner and outer ring.

2 - Sealing Element or Called Winding Ring

Why spiral wound gasket called this name? As it has a sealing element called winding ring, it is manufactured by spirally winding a V-shaped or W shaped stainless steel strip and a strip of non-metallic filler such as PTFE or Graphite. The metal strip holds the filler, providing the gasket with mechanical resistance and resilience. So now let's learn more about how to manufacture the sealing element ring.

The sealing element is produced by 2 types of spiral wound gasket winding machine, a vertical winding process for smaller diameters below 300mm, and a horizontal spiral wound gasket winding machine process for larger diameter over 300mm. Both processes are identical other than the orientation of the winding process. Except for the direction of the winding process, the two processes are the same, But a horizontal Spiral Wound Gasket winding machine has the capability of producing big size sealing elements, but it requires more floor space.

The process begins by setting an inner ring or on the main driving component of the spiral wound gasket winding machine. This machine will rotate the inner ring which will provide the necessary pulling force required to wind the sealing element. And then long metal strip will be fed into a set of profile rollers and then pulled towards the inner ring. After some circules with the inner ring, the metal winding filler and soft material filler such as graphite or ptfe together combine the sealing element. The process ends till reach enough size for the sealing element needs

3. Assembly

To finish a CGI type spiral wound gasket with inner and outer ring, or CG style spiral wound gasket with outer centering guide ring, the final stage is to snap the outer ring on around the sealing element. This is done by simply guiding the outer profiled edge of sealing element into profiled concave groove of the outer ring. If required, a mallet can be used to lightly tap the sealing element into the groove.

Also, after assembling, the outer ring need to be marked as standard or customers' need.