<SEC-DOCUMENT>0000892553-18-000027.txt : 20180104
<SEC-HEADER>0000892553-18-000027.hdr.sgml : 20180104
<ACCEPTANCE-DATETIME>20180104165747
ACCESSION NUMBER:		0000892553-18-000027
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20180102
FILED AS OF DATE:		20180104
DATE AS OF CHANGE:		20180104

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			YOUNGBERG DEWAYNE R
		CENTRAL INDEX KEY:			0001243055

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-11442
		FILM NUMBER:		18510806

	MAIL ADDRESS:	
		STREET 1:		3055 TORRINGTON DRIVE
		CITY:			BALL GROUND
		STATE:			GA
		ZIP:			30107

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CHART INDUSTRIES INC
		CENTRAL INDEX KEY:			0000892553
		STANDARD INDUSTRIAL CLASSIFICATION:	FABRICATED PLATE WORK (BOILER SHOPS) [3443]
		IRS NUMBER:				341712937
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		3055 TORRINGTON DRIVE
		CITY:			BALL GROUND
		STATE:			GA
		ZIP:			30107
		BUSINESS PHONE:		770-721-8800

	MAIL ADDRESS:	
		STREET 1:		3055 TORRINGTON DRIVE
		CITY:			BALL GROUND
		STATE:			GA
		ZIP:			30107
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_151510305362548.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2018-01-02</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001243055</rptOwnerCik>
            <rptOwnerName>YOUNGBERG DEWAYNE R</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>3055 TORRINGTON DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>BALL GROUND</rptOwnerCity>
            <rptOwnerState>GA</rptOwnerState>
            <rptOwnerZipCode>30107</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>VP, GC and Secretary</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common stock, par value $0.01 per share</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2018-01-02</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2260</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2260</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>48.39</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2018-01-02</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>7590</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2028-01-02</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>7590.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>7590</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">These restricted share units were granted on January 2, 2018 pursuant to the Chart Industries, Inc. 2017 Omnibus Equity Plan in an exempt transaction under Rule 16b-3.  Shares of Company common stock will be issued with respect to one-third (1/3) of the total number of shares on each of the first three anniversaries of the date of grant, subject to tax withholding requirements.</footnote>
        <footnote id="F2">These options were granted on January 2, 2018 pursuant to the Chart Industries, Inc. 2017 Omnibus Equity Plan in an exempt transaction under Rule 16b-3. The options vest with respect to one-fourth (1/4) of the total number of shares of common stock underlying the stock options on each of the first four anniversaries of the date of grant.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ DeWayne Youngberg, by Derek B. Swanson, his attorney-in-fact</signatureName>
        <signatureDate>2018-01-04</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
