Chemical Engineering vocabulary · Plant Equipment and Operations
Off-spec
Meaning in chemical engineering, with examples
/ˌɔːfˈspɛk/adjectiveCommon term
In chemical engineering, off-spec means: Describes a product or stream that does not meet its required specification, for example too much water, the wrong color or too low a purity.
In Turkish: şartname dışı, spesifikasyon dışı, standart dışı
How it is used
Used in operations, quality control and planning. Off-spec product is sent to a slop tank, reprocessed, blended or sold at a lower price. The opposite is 'on-spec' or 'in spec'. Short for 'off-specification'.
Example sentences
The product went off-spec for six hours after the reboiler upset.
Send the off-spec material to tank 12 for reprocessing.
Common collocations
off-spec product
go off-spec
off-spec material
back on spec
Related terms
by-productA substance made in a process alongside the main product. It may be sold, used elsewhere in the plant, or treated as waste.
storage tankA large container, usually at or near atmospheric pressure, used to hold raw materials, intermediates or products before they are used or shipped.
start-upThe process of bringing a unit or plant from a shut-down state to normal operating conditions, following a written procedure step by step.
throughputThe amount of material that a unit or plant processes in a given time, for example tonnes of feed per day.
