Five of the defendants were handed life sentences, one was given 10 years behind bars and another five years, the state-run Bahrain News Agency (BNA) reported.
The charges included forming a “terrorist group” and “training in the use of weapons and explosives,” BNA said.
The kingdom has stripped hundreds of its citizens of their nationality and jailed dozens of prominent activists and religious leaders since Shia-led protests demanding an elected government erupted in early 2011.
The Bahraini government has accused Iran of backing the protests and attempting to overthrow the government.
Tehran denies any involvement in the unrest.
The November 2017 blast cut off the pipeline linking Bahrain’s Bapco refinery with oil giant Aramco’s main pumping station in neighbouring Saudi Arabia‘s Dhahran province.
Bahrain in February accused Iran of training and arming at least two of those involved in the explosion.
Under the country’s citizenship law, amended after unrest broke out in 2011, the authorities can revoke the nationality of anyone who engages in acts deemed “disloyal” to the state.