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EP-4741697-A1 - DRAIN PLUG WITH CURVED BASE

EP4741697A1EP 4741697 A1EP4741697 A1EP 4741697A1EP-4741697-A1

Abstract

The invention relates to a drain plug (1) for draining water or moisture via a draining hole (4) from an inner region of an associated insulation system (3) having a curved outer surface (2) at a location where the draining is to take place. The draining plug comprises a tubular neck (5) with a through-going opening (11) and a liner of sealing material (12) arranged on an inner surface (13) of the opening. The sealing material expands upon exposure to temperatures above a threshold temperature and thereby closes the opening. The drain plug further comprises a base (5) located at an end (14) of the neck and extending laterally outwards from an outer surface (15) of the neck. The base has a curved mounting surface (16) facing away from the neck. In some embodiments of the invention, the base is single-curved.

Inventors

  • SCHLYTTER-HENRICHSEN, Christian

Assignees

  • Favuseal AS

Dates

Publication Date
20260513
Application Date
20241108

Claims (9)

  1. Drain plug (1) for draining water or moisture via a draining hole (4) from an inner region of an associated insulation system (3) having a curved outer surface (2) at a location where the draining is to take place, the draining plug (1) comprising: - a tubular neck (10) with: - a through-going opening (11), and - a liner of sealing material (12) arranged on an inner surface (13) of the opening (11), which sealing material (12) expands upon exposure to temperatures above a threshold temperature and thereby closes the opening (11), - a base (5) located at an end (14) of the neck (10) and extending laterally outwards from an outer surface (15) of the neck (10), wherein the base (5) has a curved mounting surface (16) facing away from the neck (10) and configured for fastening to the outer surface (2) during use.
  2. Drain plug (1) according to claim 1, wherein the mounting surface (16) of the base (5) is single-curved so that it is configured for fastening on a single-curved outer surface (2) of an associated insulation system (3) during use.
  3. Drain plug (1) according to claim 1 or 2, wherein a radius of curvature of the mounting surface (16) is 50-100 mm, such as 70-80 mm, such as 75 mm.
  4. Draining plug (1) according to any of the preceding claims, wherein the base (5) has a constant or substantially constant thickness.
  5. Drain plug (1) according to any of the preceding claims, wherein a length (L) of the neck (10) is larger than an outer cross-sectional dimension (D) of the neck (10), such as an outer diameter of the neck.
  6. Drain plug (1) according to any of the preceding claims, wherein the neck (10) and the base (5) are made as a unitary component, such as cast as one unit.
  7. Drain plug (1) according to any of the preceding claims, wherein the neck (10) and base (5) are made from metal, such as stainless steel, such as AISI 316 SS steel.
  8. Drain plug (1) according to any of the preceding claims, wherein the sealing material (12) is a graphite-based intumescent that expands at least 1000%, such as at least 2000%, such as at least 4000%, such as at least 5000%, when exposed to temperatures of above 200 degrees Celsius.
  9. Drain plug (1) according to any of the preceding claims, wherein the base (5) is provided with a plurality of circumferentially arranged through-going mounting holes (17) for receiving fasteners, such as pop rivets, when the drain plug (1) is fastened to the associated insulation system (3) during use.

Description

FIELD OF THE INVENTION The present invention relates to a drain plug for draining water or moisture from an inner region of an associated insulation system having a curved outer surface at a location where the draining is to take place. BACKGROUND OF THE INVENTION The invention has been developed for use in relation to pipes which are covered with an insulation system comprising an insulation surrounded by a metal cladding in order to provide at least fire protection to the pipes. When the pipes are made from steel, water or moisture ingress in the insulation system can lead to Corrosion Under Insulation (CUI) of the steel pipes, flanges, valves and other critical equipment arranged within the insulation. To avoid this, drain plugs are typically arranged spaced apart along the length of the pipes for draining water or moisture via a draining hole from an inner region of the insulation system. Such a drain plug may e.g. be in the form of a tubular neck with a base extending outwards from an outer surface of the neck. The base is used for mounting the drain plug e.g. by use of pop rivets so that the mounting can take place from the outside of the metal cladding only. Known drain plugs have a flat mounting surface which can be difficult to mount on a curved surface having a small radius of curvature. At least for some sizes, it is necessary to deform the base with pliers and hammers to enable the mounting. This is time consuming and may cause damage to the integrity of the drain plug. OBJECT OF THE INVENTION It is an object of the present invention to provide a drain plug which is easy to mount on a curved surface having small radius of curvature. It is another object of the present invention to provide a drain plug which is easier to mount on a curved surface having so small a radius of curvature that the use of a known drain plug would require bending of the base by use of e.g. pliers and hammers during mounting. It is a further object of the present invention to provide an alternative to the prior art. In particular, it may be seen as an object of the present invention to provide a drain plug that solves the above-mentioned problems of the prior art. SUMMARY OF THE INVENTION The above-described object and several other objects are intended to be obtained in a first aspect of the invention by providing a drain plug for draining water or moisture via a draining hole from an inner region of an associated insulation system having a curved outer surface at a location where the draining is to take place, the draining plug comprising: a tubular neck with: a through-going opening, anda liner of sealing material arranged on an inner surface of the opening, which sealing material expands upon exposure to temperatures above a threshold temperature and thereby closes the opening,a base located at an end of the neck and extending laterally outwards from an outer surface of the neck, wherein the base has a curved mounting surface facing away from the neck and configured for fastening to the outer surface during use. The tubular neck will typically have a circular cross-section, but it may also have other shapes, such as rectangular or elliptical. The liner of sealing material provides fire protection by covering the opening in the neck with expanded material so that the excessive heat from a fire is prevented from or delayed in reaching whatever is covered by the insulation system. This function is known on its own from known drain plugs. By using known designs of the neck part of the drain plug, previously performed fire tests and certification can be reused for the drain plugs according to the present invention. Such known drain plugs have typically been tested in accordance with EN1363-2 (HCF/Pool), OTI 95 634 (Jetfire), ISO-22899-1 (Jetfire) and ISO-22899-1 High Heat Flux Jetfire. The base of the drain plug typically extends around the whole circumference of the neck as will be shown in the figures. However, the scope of protection also covers drain plugs with a base extending from only a part of the outer surface of the neck if desired e.g. in relation to special space requirements for the mounting. In some embodiments of the invention, the mounting surface of the base is single-curved so that it is configured for fastening on a single-curved outer surface of an associated insulation system during use. Such a geometry is e.g. relevant in relation to pipes. In some embodiments of the invention, a radius of curvature of the mounting surface is 50-100 mm, such as 70-80 mm, such as 75 mm. The radius of curvature of the mounting surface does not need to match exactly with that of the outer surface of the insulation system. Typically, a given drain plug can be used for a range of outer surfaces as will be shown in the figures. The base may have a constant or substantially constant thickness. Hereby reference is made to a direction normal to the mounting surface. By "substantially" is meant that the thickness may vary slig