CLA-2 CO:R:C:G 086539 CMS
7508.00.50, 7616.90.00
District Director Of Customs
111 W. West Huron St.
Buffalo, NY 14202
RE: Rupture Discs and Safety Head Components
Dear Sir,
This responds to your Request for Internal Advice No. 76/89,
CLA-1-0:COD:GB, dated December 20, 1989, regarding the
classification of certain rupture discs and safety heads.
FACTS:
The merchandise consists of rupture discs, vacuum supports
and safety head inlet and outlet casings. Rupture discs are thin
metal diaphragms which burst when subjected to a predetermined
amount of pressure. The vacuum supports are metal articles which
hold prebulged rupture discs against vacuum or reverse pressure.
The inlet and outlet safety head casings are metal articles which
hold the rupture discs in place when affixed to pipes or other
components of pressurized systems. The articles function as
pressure relief safety devices.
The rupture discs are available in aluminum, copper,
stainless steel, nickel, monel (an alloy of approximately 70%
nickel and 30% copper) and inconel (an alloy of approximately 80%
nickel, 14% chromium and 6% iron). The Type PB rupture discs may
be lined with teflon or lead, or coated with a variety of
corrosion resistant plastics. The type PBV disc is a type PB
disc supplied with a vacuum support. The type D disc has two
components called the cap and seal. The cap is always metal. The
seal may be teflon or metal. Of the two components, the cap has
more mass and is the most similar to a single element rupture
disc. The type DV disc is a type D disc with a vacuum support.
The type TMT disc is similar to the type D and DV discs but has
top and bottom teflon linings. The type SB disc is a single
element disc.
-2-
The vacuum supports and safety head inlet and outlet casings
are available in aluminum, copper, stainless steel, nickel, monel
and inconel. The rupture discs, when entered with vacuum
supports and safety head inlet and outlet casings, are packaged
with other rupture discs and are invoiced separately from the
other components.
ISSUE:
Is the merchandise classified as valves or parts of valves
in Heading 8481, or according to the constituent material as
other articles of aluminum in Heading 7616, other articles of
copper in Heading 7419 and similar provisions for other metals?
LAW AND ANALYSIS:
Heading 8481 in pertinent part describes "[t]aps, cocks,
valves and similar appliances...". The Explanatory Notes to
Heading 8481, p. 1321, provide:
The appliances regulate the flow by opening or
closing an aperture (e.g., gate, disc, ball, plug
needle or diaphragm). They may be operated by hand
(by means of a key, wheel, press button, etc.), or
by a motor, solenoid, clock movement, etc., or by
an automatic device such as a spring, counterweight,
float lever, thermostatic element or pressure capsule.
The articles under consideration might regulate flow by
relieving pressure at a certain level, but they do not operate
like the valves described in the Explanatory Notes to Heading
8481. Instead of regulating flow by opening or closing an
aperture, the rupture discs burst at a particular pressure and
remain ruptured until they are replaced. The articles have no
moving parts.
The Explanatory Notes to Heading 8481, p. 1332 provide that
bursting discs are not classified as Heading 8481 valves,
stating:
Bursting discs (thin discs of plastics or metal)
are used in certain cases as safety devices instead
of valves; they are mounted by means of a special
carrier on pipe systems or pressure vessels and burst
at a specific pressure. They are classified according
to the constituent material (headings 39.26, 71.15,
73.26, 74.19, 75.08, 76.16, etc.). (underscoring added)
The articles under consideration are classified
according to their constituent material (e.g., other articles of
-3-
aluminum, Heading 7616; other articles of iron or steel, Heading
7326, etc.).
Rupture discs of base metals which are lined or coated with
different base metals are classified according to predominate
weight pursuant to Section XV Note 5.
Rupture discs of base metals which are coated or lined with
non-metals are GRI 3(b) composite goods. They are classified
according to the predominate metal because the metal parts of the
articles impart their essential character.
Rupture discs consisting of a cap and a seal are GRI 3(b)
composite goods classified according to the cap because the cap
is the component which imparts the essential character. The cap
is the more massive component, is more similar than the seal to a
single element rupture disc and has a more important role in the
operation of the article. Rupture discs supplied with a vacuum
support are classified according to the rupture disc.
Vacuum supports and safety head inlet and outlet casings are
classified according to their predominate constituent material.
Metal alloys present in any of the articles under
consideration are classified according to the predominate metal
pursuant to Section XV Note 3.
HOLDING:
The rupture discs, vacuum supports and safety head inlet and
outlet casings are classified according to their constituent
material, pursuant to Section XV Notes 3 and 5, as other
articles of iron or steel in subheading 7326.90.90, other
articles of copper in Heading 7419.99.50 other articles of nickel
in subheading 7508.00.50 or as other articles of aluminum in
subheading 7616.90.00.
Metal rupture discs, vacuum supports or safety head inlet
or outlet casings lined or coated with plastics are classified
according to the predominate metal. Rupture discs consisting of
a cap and a seal are classified according to the cap. Rupture
discs supplied with a vacuum support are classified according to
the rupture disc. A copy of this decision should be forwarded to
the internal advice applicant.
Sincerely,
John Durant, Director
Commercial Rulings Division