There are so many different hydraulic hose standards , have you been considering these meanings for you and your applications ?
For decades, SAE J517 has published guidelines for 100R1 through 100R12 series hydraulic hoses. These manufacturer-driven SAE standards have been based on design, construction, and pressure ratings to ensure that hydraulic hoses meet minimum construction requirements. SAE established minimum pressure ratings for various hose IDs (inside diameters) and were later revised to also include constant-pressure hoses, such as R13, R15, R17 and R19, which are hoses that maintain pressure ratings within a group regardless of size.
More recently, however, hydraulic system designers began adopting ISO specifications. Many large OEMs switched to ISO standards in their design and manufacturing process to ensure the sale and service of their equipment globally.