Partial Stroke Testing; Pst Configuration - Baker Hughes Masoneilan SVI II ESD Quick Start Manual

Sil3 emergency shutdown device & pst controller

Table of Contents

Partial Stroke Testing

Key components of Safety Instrumented System (SIS) are final control elements such as emer-

gency shutdown devices, i.e. the SVI II ESD. The SVI II ESD and it's associated valve are not con-

tinually moving like a typical control valve, but are normally expected to remain static in one

position and then reliably operate upon an emergency situation. Valves that remain in one posi-

tion for long periods of time can be become stuck in that position and may not operate when

needed. To ensure the integrity of the ESD valve the SVI II ESD requires periodic testing.

One of the great features of the SVI II ESD is the ability to test the safety valve on-line, without

removing the safety valve from the SIS. The SVI II ESD allows you to automatically, or on demand

perform a Partial Stroke Test (PST) which returns relevant variables about valve operation and

can allow you to detect potentially dangerous failures.

Before running PST, configure the parameters; travel, maximum pressure, maximum time, ramp

speed, and spring. You can configure PST parameters from the pushbutton display and also us-

ing ValVue ESD. Refer to Table 6 on page 56 for PST configuration parameters.

PST Configuration with Display

When using the LCD display to configure PST:

1. Aces the PST Configuration (PST CONF) menu. (Refer to Figure 21 on page 61 for

menu structure.).

2. Scroll through each PST parameter and adjust accordingly.

PST Configuration with ValVue ESD

When using ValVue ESD to configure PST:

1. Select the Configure screen in ValVue ESD.

2. Set the PST parameters to the appropriate settings.

3. Apply and save changes.

70 | =BHGE

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Masoneilan svi ii esd sil3