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<!--Generated by DFIN XBRL Instance Document - http://www.dfinsolutions.com/ - Version R3.0 - on 22-March-2025 [06:55:09] {AM}-->
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_grc_ClosingSharePrice" xml:lang="en-US">Closing Share Price</label>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_grc_ClosingSharePrice" xml:lang="en-US">Closing share price.</label>
<loc xlink:type="locator" xlink:href="grc-20241231.xsd#grc_ChangeInPensionValueNetOfServiceCostMember" xlink:label="loc_grc_ChangeInPensionValueNetOfServiceCostMember" />
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<loc xlink:type="locator" xlink:href="grc-20241231.xsd#grc_CurrentYearGrantsMember" xlink:label="loc_grc_CurrentYearGrantsMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_grc_CurrentYearGrantsMember" xml:lang="en-US">Current Year Grants [Member]</label>
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<loc xlink:type="locator" xlink:href="grc-20241231.xsd#grc_GrantsFromPriorYearsForfeitedInCurrentYearMember" xlink:label="loc_grc_GrantsFromPriorYearsForfeitedInCurrentYearMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_grc_GrantsFromPriorYearsForfeitedInCurrentYearMember" xml:lang="en-US">Grants from Prior Years Forfeited in Current Year [Member]</label>
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<loc xlink:type="locator" xlink:href="grc-20241231.xsd#grc_GrantsVestingInCurrentYearMember" xlink:label="loc_grc_GrantsVestingInCurrentYearMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_grc_GrantsVestingInCurrentYearMember" xml:lang="en-US">Grants Vesting in Current Year [Member]</label>
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<loc xlink:type="locator" xlink:href="grc-20241231.xsd#grc_PriorYearGrantsMember" xlink:label="loc_grc_PriorYearGrantsMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_grc_PriorYearGrantsMember" xml:lang="en-US">Prior Year Grants [Member]</label>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_grc_PriorYearGrantsMember" xlink:to="lab_grc_PriorYearGrantsMember" />
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