Amazing Difference between API Std, API RP and API MPMS
API (American Petroleum Industry’s) MPMS
API MPMS stands for Manual of petroleum measurement standards
We know that petroleum products have an equivalent cost associated with them.
Hence the measurement of petroleum products like natural gas have to be more precise than that of utility services like stem or instrument air.
Thus API Standards committee came up with API MPMS standards that especially cater to measurement of petroleum products.
Example :- Orifice flow meters.
The ISO standard for Orifice flow meters is ISO 5167 part 2
While, The API standard for orifice flowmeter measuring natural gas and other related hydrocarbon is API MPMS 14.3 (Which consists of Part 1, 2 and 3)
Although both the standards cater to orifice flow meter, The API MPMS standard is far conservative and has stringent requirements as compared to ISO standard.
Thus if we are measuring the flow of stem ISO 5167 might be sufficient however for Natural gas measurement API MPMS standard would be the recommended option.
We know that petroleum products have an equivalent cost associated with them.
Hence the measurement of petroleum products like natural gas have to be more precise than that of utility services like stem or instrument air.
Thus API Standards committee came up with API MPMS standards that especially cater to measurement of petroleum products.
Example :- Orifice flow meters.
The ISO standard for Orifice flow meters is ISO 5167 part 2
While, The API standard for orifice flowmeter measuring natural gas and other related hydrocarbon is API MPMS 14.3 (Which consists of Part 1, 2 and 3)
Although both the standards cater to orifice flow meter, The API MPMS standard is far conservative and has stringent requirements as compared to ISO standard.
Thus if we are measuring the flow of stem ISO 5167 might be sufficient however for Natural gas measurement API MPMS standard would be the recommended option.
API (American Petroleum Industry’s) RP
API RP stands for API Recommended practice.
My personal name for these standards is “having a candid discussion with experts”
We know that any remarkable engineering feat has never been created by a single individual alone.
It has always been a collaboration of various smart minds, past experiences and lessons learn that have made such feats a reality.
Thus API came with RP which acts like a store house of best practices for engineering.
Example : We know that a lot of devastating accidents have happened due to failure of valves in FCCU unit.
API RP 615 capture the best practices and possible issues faced in refinery including recommendations for FCCU valves.
What is API RP not about ?
These are not enforceable standards.
Example API 526 Standard is a relief valve standard that could be enforceable by client if they adopt it. (i.e. orifice area of relief valves etc.)
However API RP 551 is recommended practices (a collection of best practices) and not mandatory practices.
My personal name for these standards is “having a candid discussion with experts”
We know that any remarkable engineering feat has never been created by a single individual alone.
It has always been a collaboration of various smart minds, past experiences and lessons learn that have made such feats a reality.
Thus API came with RP which acts like a store house of best practices for engineering.
Example : We know that a lot of devastating accidents have happened due to failure of valves in FCCU unit.
API RP 615 capture the best practices and possible issues faced in refinery including recommendations for FCCU valves.
What is API RP not about ?
These are not enforceable standards.
Example API 526 Standard is a relief valve standard that could be enforceable by client if they adopt it. (i.e. orifice area of relief valves etc.)
However API RP 551 is recommended practices (a collection of best practices) and not mandatory practices.
Personal Story
During one of my Projects the vendor had provided FKM Viton gasket for Steam service and I raised a query about the selection of gasket.
Since the vendor was also world renowned, they did not pay attention to this query and stated that this is their standard offering.
So, I suggested that API 551 RP states that FKM Viton gasket is not suitable for steam service.
We suggested that if they would provide a written confirmation that this would not cause any issue in the plant then we would be glad to accept their offering.
Guess What? Next day we received a revised quote with PTFE gasket at no additional cost. 😊
Since the vendor was also world renowned, they did not pay attention to this query and stated that this is their standard offering.
So, I suggested that API 551 RP states that FKM Viton gasket is not suitable for steam service.
We suggested that if they would provide a written confirmation that this would not cause any issue in the plant then we would be glad to accept their offering.
Guess What? Next day we received a revised quote with PTFE gasket at no additional cost. 😊
API (American Petroleum Industry’s) Std
These act like the regular standards which when specified vendor’s need to comply.
Example the Orifice designation specified in API 526 standard for relief valves have a particular size that needs to be complied.
So if a vendor is required to comply to API 526 std then they must follow the orifice designations and its corresponding dimensions.
If a vendor does not comply due to some special condition then it is vendor’s responsibility to notify the client.
PS: This is as per best of my current understanding, If you have any other opinions please feel free to reach out to me via “contact me” page.
I always enjoy technical discussion 😊
Example the Orifice designation specified in API 526 standard for relief valves have a particular size that needs to be complied.
So if a vendor is required to comply to API 526 std then they must follow the orifice designations and its corresponding dimensions.
If a vendor does not comply due to some special condition then it is vendor’s responsibility to notify the client.
PS: This is as per best of my current understanding, If you have any other opinions please feel free to reach out to me via “contact me” page.
I always enjoy technical discussion 😊
