This is a basic form the rings to seal up stems of fittings are made by moulding a graphite foil up to required density (see the table), usually within 1.3÷1.8 g/cm3 ( standard d ensity: 1 .4g/cm3). The cross-section of the Graf met ^® 950 ring is usually a square, however a rectangular cross-section is also available. Grafmet^® 950 has a high ratio K of transformation of axial stress forces into radial stress forces (0.8÷0.9, depending on its density). They are made of various types of graphite foil – see the table. As a standard, if no other designation is provided, rings are made of Sigraflex^® C foil. When other types of foil are used, it is designated adequately, for instance: Grafmet^® 950 TF, etc. Grafmet^® 950 can be used i ndividually ( new fittings with stems of rather small diameters, systems of rather low pressure) or in sets (see: valve stuffing-box sets) as main rings responsible for sealing. It is also a component of special packing sets.

Its construction form has an appearance nearing to Grafmet^® 950, but it is strengthened with an internal reinforcement of 316L grade steel. The reinforcement is designed to improve mechanical extrusion resistance. Usually it is made of Sigraflex^® C graphite foil. Its principal application is to work as a closing rings (top or bottom ring) in a sealing packet (e.g. SPETOPAK^® WGR 951/950). Its function is to prevent extrusion of the proper sealing material into gaps around a gland and/or in the bottom of a stuffing-box. The Grafmet^® 950 I r ing c an b e used as a distance piece in a l ong stuffing-box (see: Grafmet^® HD). Aslo other materials (e.g. nickel foil) can be used as a reinforcement in special products, and the rings can be made of other types of the Sigraflex^® foil.

This is a basic form the rings to seal up stems of fittings are made by moulding a graphite foil up to required density (see the table), usually within 1.3÷1.8 g/cm3 ( standard d ensity: 1 .4g/cm3). The cross-section of the Grafmet^® 950 ring is usually a square, however a rectangular cross-section is also available. Grafmet^® 950 h as a high ratio K of transformation of axial stress forces into radial stress forces (0.8÷0.9, depending on its density). They are made of various types of graphite foil – see the table. As a standard, if no other designation is provided, rings are made of Sigraflex^® C foil. When other types of foil are used, it is designated adequately, for instance: Grafmet^® 950 TF, etc. Grafmet^® 950 can be used i ndividually ( new fittings with stems of rather small diameters, systems of rather low pressure) or in sets (see: valve stuffing-box sets) as main rings responsible for sealing. It is also a component of special packing sets.

Its construction form has an appearance nearing to Grafmet^® 950, but it is strengthened with an internal reinforcement of 316L grade steel. The reinforcement is designed to improve mechanical extrusion resistance. Usually it is made of Sigraflex^® C graphite foil. Its principal application is to work as a closing rings (top or bottom ring) in a sealing packet (e.g. SPETOPAK^® WGR 951/950). Its function is to prevent extrusion of the proper sealing material into gaps around a gland and/or in the bottom of a stuffing-box. The Grafmet^® 950 I r ing c an b e used as a distance piece in a l ong stuffing-box (see: Grafmet^® HD). Aslo other materials (e.g. nickel foil) can be used as a reinforcement in special products, and the rings can be made of other types of the Sigraflex^® foil.

The rings are conformable, in their essence, with descriptions of construction forms of the Grafmet^® 950 and Grafmet^® 950 I respectively. Their differences to the above consist in two cuts in their circumferences facilitating assembly operations. Unlike the rings with one cut, the piece with two cuts is not deformed during assembly. Hence, the ring of even very small diameter and considerable width can be used without risk of damage is sealing functions. Of course, correct installation requires accuracy and compliance to the rule that a cut in every layer is turned by 90° to the other one. Particularly such a construction is required for rings relatively stiff (due to high density) or inserted with a metal foil. In such situations two cuts provide real facility in assembly.

Grafmet^® 950 IPP rings are normally made of the Sigraflex^® C foil having a standard density of graphite 1.4g/cm3. Other densities and/or types of foil are also available, thus the specific requirement should be indicated in the order.

The ring of such a form is designed to protect against squeezing (flowing) of the sealing material (graphite) into gaps existing on place of its application. Another function is to minimize access of oxygen to graphite. The ring can be used individually in static applications as sealing of a cylindrical surfaces, and/or as an upper/lower ring in a packet sealing a stuffing-box. In such a case, forged material of low tacking to the stem material is recommended (see also: WGR 952/950), as for instance nickel. Applying to systems of high pressure, density of graphite is recommended to be selected according to the working pressure (see the table), the standard density of the product is 1.6g/cm3 and the product itself is made of Sigraflex^® C foil. In case of power system applications, Sigraflex^® P foil is recommended (designation is: Grafmet^® 952 HTX).

The rings Grafmet^® Profil#... w ith respective description are u se in, according to an individual design, machine, fittings, and/or pump construction. Their use is related to simplification of their structures by implementation of special sealing profiles. It allows, for instance, to reduce the number of components, to decrease a joint outline by separation three rooms (areas) with one seal, to reduce void pockets, to facilitate assembly operations. Parameters that can be assorted by SPETECH^® while manufacture of Grafmet^® Profil#... profiled rings, are: geometry, density (density distribution), stiffness/hardness, split or not split, etc. Adjustments are made directly with the constructor of the equipment. Sealing of diameters up to 2000mm are available, density from 1.1g/cm3 up to 1.9g/cm3. The above solutions can contain metal pieces pressed in, and can be an integral part of a constructure, and not only a sealing.