Ball valve and valve operating method

A ball valve to regulate, direct or control a fluid flow through the valve, comprising:

• a body with a first port, a second port and an interior space extending between the first and second port;
• a seat arranged in the interior space of the body;
• a valve member moveably arranged inside the interior space of the body to cooperate with the seat;
• and
• a stem engaging with the valve member to move the valve member,
• wherein the valve member includes a valve disc configured to engage with the seat in an engagement position of the valve member,
• wherein the valve member is moveable between the engagement position and a first position via a second position, wherein in the second position of the valve member the valve disc is aligned with the seat at a distance from the seat, wherein in the first position of the valve member the valve disc is at a larger distance from the seat than in the second position,
• wherein the valve member is rotatable between the first position and the second position with the valve disc maintaining a distance from the seat and the body,
• and wherein the valve member is moveable between the second position and the engagement position in a direction substantially perpendicular to a contact plane defined by the seat,
• wherein the stem is rotatable about a longitudinal axis thereof between a first rotational position corresponding to the first position of the valve member and a third rotational position corresponding to the engagement position of the valve member with a second rotational position corresponding to the second position of the valve member in between the first and third rotational position,
• wherein in between the first and second rotational position of the stem the valve member and the stem are coupled according to a first configuration allowing to move the valve member between the first position and the second position,
• and wherein in between the second and third rotational position of the stem, the valve member and the stem are coupled according to a second configuration different from the first configuration allowing to move the valve member between the second position and the engagement position, and
• wherein the ball valve is configured such that the stem is rotated 90 degrees between the first rotational position and the third rotational position.

A method to operate a ball valve to regulate, direct or control a fluid flow through the valve, said valve comprising:

• a body with a first port, a second port and an interior space extending between the first and second port;
• a seat arranged in the interior space of the body;
• a valve member moveably arranged inside the interior space of the body to cooperate with the seat, wherein the valve member includes a valve disc configured to engage with the seat in an engagement position of the valve member;
• and
• a stem engaging with the valve member to move the valve member,
• and said method comprising the following steps:
• a) rotating the stem about a longitudinal axis thereof from a first rotational position corresponding to a first position of the valve member to a second rotational position corresponding to a second position of the valve member, wherein in the second position of the valve member the valve disc is aligned with the seat at a distance from the seat, wherein in the first position of the valve member the valve disc is at a larger distance from the seat than in the second position, and wherein the valve member is rotated due to a first coupling configuration between the valve member and the stem from the first position to the second position with the valve disc maintaining a distance from the seat and the body;
• and
• b) rotating the stem further from the second rotational position to a third rotational position corresponding to the engagement position of the valve member, wherein the valve member is moved due to a second coupling configuration between the valve member and the stem that is different from the first coupling configuration from the second position to the engagement position in a direction substantially perpendicular to a contact plane defined by the seat, and
• wherein the stem is rotated 90 degrees between the first rotational position and the third rotational position.