Chemical injection mandrel pressure shut off device

A method comprising:

• discharging a chemical fluid from outside a wellbore to a mandrel channel through a chemical flow line in a shut off system;
• where the shut off system comprises:
• an inline valve assembly comprising:
• a nipple comprising a chemical flow line;
• the chemical flow line being operative to transfer fluids from outside the wellbore to a mandrel channel;
• where the mandrel channel is disposed in the mandrel;
• a valve assembly comprising:
• a cylinder and a piston shaft;
• where the cylinder contacts the chemical flow line;
• where the piston shaft reciprocates in the cylinder in response to opposing applied pressures;
• where the piston shaft contacts a sealing object that is operative to facilitate or to prevent fluid flow from the chemical flow line to the mandrel channel;
• where the cylinder comprises a port that provides fluid communication from the cylinder to the mandrel channel;
• and
• an actuating assembly;
• where the actuating assembly is operative to displace the piston shaft in the cylinder;
• increasing the pressure of the fluid in the chemical flow line to exceed the pressure exerted by the actuating system on the piston shaft;
• displacing the sealing object from the chemical flow line;
• and
• facilitating the flow of fluid from the chemical flow line to the mandrel channel.