Standards, abbreviated as STD, are developed by trade associations, government agencies and private companies.  They are meant to provide a minimum set of guidelines for engineering and construction.  But by no means are these rules to be a substitute for good engineering practices.

standards associations

• American Gear Manufacturers Association (AGMA) 
• American Iron and Steel Institute (AISI) 
• American National Standards Institute (ANSI) 
• American Petroleum Institute (API)
• American Society of Mechanical Engineers (ASME)
• American Society of Safety Engineers (ASSE)
• American Society of Sanitary Engineering (ASSE)
• American Society for Testing and Materials (ASTM)
• American Welding Society (AWS)
• American Water Works Association (AWWA)
• British Standards Institution (BSI)
• Hydraulic Institute (HI)
• Instrument Society of America (ISA)
• International Organization for Standardization (ISO)
• Manufacturers Standardization Society (MSS)
• National Association of Corrosion Engineers (NACE)
• National Electrical Manufactures Association (NEMA)
• National Fire Protection Association (NFPA)
• National Institute of Standards and Technology (NIST)
• Occupational Safety and Health Administration (OSHA)
• Society of Automotive Engineers International (SAE)