For B2B buyers, compliance is non-negotiable. Ensure the meter body is made of corrosion-resistant materials like Brass (DZR), Stainless Steel (304/316), or Epoxy-coated Cast Iron. For potable water applications, look for WRAS, NSF/ANSI 61, or ACS certifications. For billing purposes in the EU, MID (Measuring Instruments Directive) certification is mandatory. For industrial safety, check for ISO 4064 standards and IP68 ingress protection if the meter will be installed in flooded pits or harsh environments.