<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2006-07-25</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000892553</issuerCik>
        <issuerName>CHART INDUSTRIES INC</issuerName>
        <issuerTradingSymbol>GTLS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001274073</rptOwnerCik>
            <rptOwnerName>FIRST RESERVE GP X INC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>ONE LAFAYETTE PLACE</rptOwnerStreet1>
            <rptOwnerStreet2>THIRD FLOOR</rptOwnerStreet2>
            <rptOwnerCity>GREENWICH</rptOwnerCity>
            <rptOwnerState>CT</rptOwnerState>
            <rptOwnerZipCode>06830</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>See Remark 1</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001274074</rptOwnerCik>
            <rptOwnerName>FIRST RESERVE GP X LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>ONE LAFAYETTE PLACE</rptOwnerStreet1>
            <rptOwnerStreet2>THIRD FLOOR</rptOwnerStreet2>
            <rptOwnerCity>GREENWICH</rptOwnerCity>
            <rptOwnerState>CT</rptOwnerState>
            <rptOwnerZipCode>06830</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>See Remark 1</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001274075</rptOwnerCik>
            <rptOwnerName>FIRST RESERVE FUND X LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>ONE LAFAYETTE PLACE</rptOwnerStreet1>
            <rptOwnerStreet2>THIRD FLOOR</rptOwnerStreet2>
            <rptOwnerCity>GREENWICH</rptOwnerCity>
            <rptOwnerState>CT</rptOwnerState>
            <rptOwnerZipCode>06830</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>See Remark 1</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001332756</rptOwnerCik>
            <rptOwnerName>Quintana Maritime Investors LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>ONE LAFAYETTE PLACE</rptOwnerStreet1>
            <rptOwnerStreet2>THIRD FLOOR</rptOwnerStreet2>
            <rptOwnerCity>GREENWICH</rptOwnerCity>
            <rptOwnerState>CT</rptOwnerState>
            <rptOwnerZipCode>06830</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>See Remark 1</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>10603192</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">This Form 3 is being filed in connection with the initial registration by Chart Industries, Inc. (the &quot;Issuer&quot;) of a class of its equity securities under Section 12 of the Exchange Act of 1934, effected via the Issuer's registration statement on Form 8-A12G (File No. 000-50412) and its related registration statement on Form S-1/A under the Securities Act of 1933, dated July 20, 2006 (File No. 333-133254).</footnote>
        <footnote id="F2">Pursuant to Rule 16a-1(a)(4) of the Securities Exchange Act of 1934, each Reporting Person states that this filing shall not be deemed an admission that such Reporting Person is the beneficial owner of any of the securities reported herein.  Additionally, each Reporting Person disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.</footnote>
        <footnote id="F3">The securities of the Issuer reported herein are directly owned by FR X Chart Holdings LLC (&quot;Holdings&quot;).  In addition to Holdings, this Form 3 is being filed on behalf of each of First Reserve GP X, Inc. (&quot;GP X Inc.&quot;), First Reserve GP X, L.P. (&quot;GP X&quot;), and First Reserve Fund X, L.P. (&quot;Fund X&quot;), each of which may be deemed to beneficially own the securities owned by Holdings.  Fund X is the sole member of Holdings. GP X is the general partner of Fund X, and GP X Inc. is the general partner of GP X.</footnote>
    </footnotes>

    <remarks>(1) The Reporting Persons have included the designation of &quot;Director&quot; in order to satisfy potential filing obligations in the event any such Reporting Persons are deemed to be a director of the Issuer by deputization.
(2) First Reserve GP X, Inc., by Anne E. Gold, Assistant Secretary, is signing for itself as the designated filer, as well as in the capacity of general partner of First Reserve GP X, L.P.  First Reserve GP X, L.P., by Anne E. Gold, is signing in its capacity as general partner of First Reserve Fund X, L.P.  First Reserve Fund X, L.P., by Anne E. Gold, is signing in its capacity as sole member of FR X Chart Holdings LLC</remarks>

    <ownerSignature>
        <signatureName>Anne E. Gold, Authorized Person (See Remark (2))</signatureName>
        <signatureDate>2006-07-25</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Anne E. Gold, In Capacity as Described in Remark 2</signatureName>
        <signatureDate>2006-07-25</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Anne E. Gold, In Capacity as Described in Remark 2</signatureName>
        <signatureDate>2006-07-25</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Anne E. Gold, In Capacity as Described in Remark 2</signatureName>
        <signatureDate>2006-07-25</signatureDate>
    </ownerSignature>
</ownershipDocument>
